I feel I should clarify some terms in regards to ECM (PCM) module design (USA based PCM hardware and software development). This may be looked at as industry jargon, but it really makes sense once you understand the complete PCM development cycle. The PCM control algorithms are called strategy. PCM code execution is done using a multitasking priority based preemptive real-time operating system, meaning processing is done concurrently on several different control systems or tasks. The processing is not parallel (because the processor usually only has one execution core) but switched between the tasks at a rate which satisfies the update requirements of the function(s), making it look as though several systems are being managed at once. Also, the PCM RTOS is a hybrid, multi-domain operating system, having algorithms execute according to time (like in seconds, or time domain) or crank position (degree rotational, or crank domain, this is why PCM execution loading increases with increasing engine RPM). A strategy can be generic across an engine family but be unique in terms of engine specifics. This list of constants used by the strategy is called a calibration. For example, you may have one engine in a family which is of a larger displacement, so the constant "map", or calibration, would be unique to this engine for volumetric efficiency or spark advance. Strategy can be generic, but calibrations are specific. The video is a bit strange if you assume the PCM is post OBD-II, and includes two way control using a scan tool, which, as most experienced diagnostic techs know, for non-oem tools is hit or miss like the Autel scan tool in the video, but many times either is useful enough to diagnose a problem, or displays a good number of PIDs (Parameter Identifiers, basically PCM variables) to allow a starting point for troubleshooting. The first step in understanding if you need to replace a post OBD-II PCM is to talk to it through a scan tool. There are a good many basic P0 OBD-II codes which pertain directly to PCM operation, so if you have stored or pending codes these will give an indication of the problem. The most effective diagnostic for understanding if you need a PCM replacement is asking the PCM. From a circuit standpoint a great many PCMs fail due to high temperatures in or around a power output stage (transistor). Other problems are related to the PCMs age, like leaking Aluminum Electrolytic capacitors (tend to fail with age) which can make a PCM have intermittent problems.
The average Home Mechanic is never going to be able to understand this information in this amount of detail. I am guessing that all of the Test Equipment used to do this work costs a Fortune. Our Vehicle Technologies are Way out of control if you ask me. No wonder the Average Person cannot afford to purchase a new vehicle. I just cannot Wrap my mind around the fact that a Basic Large Pick Up Truck for instance may cost anywhere from $40,000 to $90,000. We must remember this is only Transportation that drops off in value as soon as you drive it off of the lot. For this kind of Money I woukd invest it in a House that may increase in value. If I was in the Market for a Truck for instance I would find an older model that is in good shape for a decent price. If I had to wind up putting $5,000 to $10,000 in it to use it reliably for several years it would be worth it.
You're reading my mind. Learning about PCMs right now because my beloved '98 Wrangler is dead because I dared splice into the wiring to install an new aftermarket gauge cluster and OH BOY am I regretting it. I fear the 'puter brayn in my Jeep is dead and am spending countless hours reasearching and parts buying and testing to only suffer increasing frustration and a reluctance to ever do my own work again. This experience makes me NOT want to buy a new car, but to buy an OLD car, one that I can fix. Everyday I hear people complaining about their (modern) cars. It seems this choice made by the auto industry to purposely complicate things is one made only of pure greed. The house I grew up in cost less than a modern car. Capitalism out of control.
It’s not so much the technology, because everything has it, it is because no one pays attention to our government and our tax dollars. Your dollars are worthless trash, they keep printing money, ( about 1 trillion every hundred days) government and big corporations are in bed together paying each other with tax dollars. You get higher costs of everything.
I agree with I just told my friend the same thing last night. If I have to spend up to 10,000 to keep my truck road worthy then so be it. I'm not paying 70,000 for a new truck now a days.
Mechanics fix vehicles, not soccer dad's or dentists. It takes a lifetime in the repair field to become well versed in auto repair. People need to stop trying to work on their own stuff, it ends up making the repair much more involved because people wanna try save a few bucks. Would you go to McDonald's and expect to find someone that can do your brain surgery?
They should make a law that if a car company makes a car with a computer, if that car has any problems that evolves the computer that they should have to fix it for free if they're going to sell them.
BRILLIANT, BRILLIANT, BRILLIANT, sorry for repeating myself but absolutely brilliant video. I know i am going to make a glutten of myself by the repeated watching of this video over and, over. Many thanks, thumbs up and subscribed.
I have found in about 50% of the cases where the flow chart call for the ecm to be replaced that pin fit is the cause. You mentioned corrosion, but GM has several TSB's concerning incorrect pin fit caused by vibration and incorrect testing methods. In addition, some manufacturers have known issues with internal faults, others not. I ALWAYS find the cause before replacement. Case in point, Ford 3.0 ignition coils causing the drivers in the ecm to fail....
@@steveolive9991 I have a 2008 Honda Civic Lx. All 4 cyl were replaced on tune up. I got a code saying all 4 are misfiring, drain bad fuel. Makes no sense. My uncle told me (mechanic for 25 years) that bad fuel wouldn't be an issue in Florida as heat would evaporate any water. I replaced my plugs & they looked okay. Still having issues. Don't know what to do now. Change the ECM? I mass air flow sensor is brand new too. What else could it be?
I was replacing my Crankshaft sensor and it broke off inside where the magnet goes l pulled on it hammered it back up in the and now my new crankshaft sensor don't fit it won't go all the way in do you think l have to replace the wheel?
"the ecm is the most expensive fuse on the car" i'm going through a rough time with my subaru right now, and that made me feel much better, at least for a moment
@@ricksmith2476 nope. i finally broke down and called a friend who runs a shop, saying i thought it was the ecm. he said, paraphrasing: "it's the most complex component, so people default to thinking it's the culprit" turned out, when i checked the fuses in my 96 subaru legacy (my first step, btw!), i missed one: buddy brought up his wiring diagrams, and had a hunch it was fuse 15. which it was. thank god.
I have a problem that's telling me the p0017 and the poo 04330 is coming up all the time even with new O2 sensors new cam sensors new crank sensors could it possibly be the ECM 2:342:352:362:37
WOW! Now I know for sure that I know absolutely nothing❗️ 🤓 Thank you… I found it inspirational and even understood < 0.095%. But really you were very clear, and not rushed at all. I’ve got a P0483 along with P0606 on 2006 Ram2500 5.9l. No idea what to do but I have cleaned all obvious grounds (just got it and it has 208k mi’s on it. One thing I have no idea about is how to find the grounds inside the wiring connectors. I do have the Dodge exhaustive wiring diagrams but am super confused about how to locate for exmpl, the fan clutch control in the Drive-Fan Radiator module, as it runs between that and the ECM (but I have the wiring diagram of that). The reason I’m looking at that is: I think there could be a connection that needs cleaning and so hopefully the ECM is really ok. Any help is appreciated! Thanks again for your efforts to help us❗️❗️ Art in FL
How are you sir i have a 2006 silverado i parked the truck trhee weeks ago running fine today I want to start the engine the battery was dead it was an old battery so i went to buy a new one after installing the battery truck doesn't start i can hear the fuel pump running when i open the ignition switch but won't start door locks doesn't work neither nor dash clusters base on ur experience u think computer is bad???????
NOW THIS WAS TRULY A TECH HELPFUL VIDEO ,,, PLEASE I HOPE TO SEE MORE HELPFUL VIDEOS LIKE THIS ONE NOT LIKE OTHERS THAT SEEM TO BE MORE LIKE COMMERCIALS FOR DIFFERENT PRODUCTS I KNOW WE ALL NEED ARE SPONSORS BUT AT LEAST SEPARATE THEM FROM THE TRUE TECH HELP VIDEOS , THANKS PET!!!!!!!!!!!!!
Noticed you video very helpfull, on a gmc acadia 3.6, ive had multiple codes and replaced many things but still car goes to limp mode and stalls will no xheck engine light do you think it could bad ecm? I got good, fuel, good air, good power , but problem is still there
Motor age this video is informative, but my problem is a little tricky. I have a 2003 chevy tahoe Z71 5.3L. Im using my snap-on solus ultra scanner. I have communication with the ecm/pcm. The vehicle starts fairly consistently, but it has started to develop an issue where it won't turn over at all. All the fuses are intact. I haven't found any obvious wiring issues. All the relays cycle as expected. The ecm/pcm just started showing an error code for a communication fault. It does this when attempting to cold start or after the engine is at operating temperature (the few time i was able to start it). I have replaced the ignition switch due to wear and it ran for approximately 3 weeks before the no crank problem returned. When it would crank I was able to read all available pids. I can read the ones that are not dependent on the engine running and haven't been able to pin the issue down. This has been an intermittent issue (about once every 2-3 months) until recently (every other day). I pulled the starter and bench tested it to eliminate it from the check list. I haven't found and fouled or damaged ground straps. Everything else seems to be in good repair at this point. Any additional insight would be greatly appreciated as I'm at a loss and really cannot afford to replace the ecm/pcm at this time.
What about when you haven't been able to to turn the engine on in a couple weeks hard to diagnose the problem after my battery died and erased my codes.. problem is that I'm not hearing the fuel pump engage fuses and relays seem to be o.k...... so I'm thinking it could be the ecm but I did a visual inspection after taking it out and the circuit board is super clean!!!!!! what should I check next......
Thanx for information about circuit and economics having poor performance and fuel consumption 3.7 2008 jeep commander New plugs are oem and clean pm service Over the past few months fuel Consumption has steadily declined Thanx again for your Video Have a Great Day 👍
OK look o have a gmc 05 pick up an the trans just started this it won't shift from 2nd to 3rd it just revs up an I went to auto zone an hooked up to read codes an one Said repair wires going to ecm where should I look also is there any way to change this to see if I can make it work so I can drive the truck
@@MotorAgeMagazine my engine had a 42 trouble code. No check engine light is on. I drained the system to try to reboot the ECM. Not sure where to start looking for the problem. I only have a 12 volt probe and a multimeter. Any advice if I need to replace the ECM? Been watching videos for days but haven't found the information that I need.
@@MotorAgeMagazine 94 GMC Sierra C300 with a 7.4 engine. Had code 42 and did a system drain to see if I could reboot the ECM. Code has disappeared and I will drive her in a bit to see if will give me any codes. The engine will rev up in park but in gear the timing doesn't seem to advance.
I don't have any scope. Got a 12 probe that has a ground lead for detecting current. I also have a multimeter. I got the code 42 on my 94 GMC Sierra C3500.
Do you have any recommendations for a 2002 dodge PCM repair its not communicating with the cam sensor no crank sensor on this model I suspect weak solder connections
I got My thermostat, Cooling fan, And Spark plugs changed.. Engine sounds good again But Rpms fluctuate and car jerks.. Also It is overheating way more than it was before I changed Thermostat and cooling fan. Was told my ECM/ECU needs to be changed on my 2007 Chevy cobalt... Not sure what to do spent 3200 On it and Now that..
Hey , I see your situation happened a year ago but do you remember how it turned out ? We have the exact same car with 302,000 mi. Things are happening now at that mileage but this one is harder to diagnose . I am a mechanic .
I can remember when electronics first came out on automobiles .... It pushed alot of machanic s out of business simply because they could not Comprehend the basics of electronics in which through them out in lelf field.... It pays to be educated .
How much for the computer reading tech? And how much for the ecm when it is the problem? Near end of season work I’m really looking for cheap solutions
Does anyone know if i can use a used ecm from a different car but the same make modle, year, engine, etc? I have a 09 corolla s and have a ecm problem. Thanks.
I need you to fix my Durango 07..i replaced all the sensors..it runs great until u try to restart vehicle..then stalls.. Replaced ignition switch, cam sensor ,crank, map, im tempted to replace pcm are fuse box
I can't afford a computer scan tool but I do have a multimeter, my 99 astro van is blowing the ecm1 and I need to fix it what video do you recomend or is it hopeless
You know your stuff! But what do I do if I have an OBD 1 port on an older car? I can't seem to find the right scan tool for my car (1992 Corvette) The data is not very deep. Without a tool, the best I can do is use the codes that come on the dash by jumping two ports on the OBD with a paper clip. In my case, I get a communications error (C41) between the ECM and the BCM. Not much help there, so what can I do?
There are DIY versions of the professional service information systems I use that you may find helpful. Here's some info I found that also might be useful: Module 1 - CCM Code 41 - Communication Error (CODE 41H History 41C Current) Problem - Central Control Module (CCM) serial communication failure The CCM requires constant encrypted data communication from the ECM at all times. The CCM communicates in a master-slave configuration, the CCM is assigned as the master and constantly polls injector and data from the ECM before startup in order for the vehicle to run and insure the VATS (Vehicle Anti-Theft System) hasn`t been bypassed. It also communicates with various other modules on the serial line reducing the number of wires required between modules.(early Canbus). This is not to be confused with ECM error code E41 (Electronic Spark Control Circuit Open) when reading ECM codes. If ECM codes (module 4) come up ERR on the LCD cluster you can scan or jump the ECM directly from the diagnostics port A,B to pull codes directly from the Check Engine Light. The C41, H41 CCM issue is mainly due to a defective ECM under the hood or open or short to ground of any of the CKT 800 (Tan) serial data communication wires and grounds between the CCM to ECM and other major computer modules behind the instrument panel. This problem can present itself on running and non-running cars depending on severity. A no start condition is typically the result from a complete ECM failure. The CCM shares serial wires and branches them from S222 behind the IP. An open or cut serial wire in the system will disable that specific module where a short will take out the entire chain. HERE IS THE INSPECTION ORDER TO THESE TARGET AREAS AND SUCCESSFUL FIXES TO THIS ISSUE: - Make sure the AIR BAG fuse is OK and I/P to DERM harness connector isn’t disconnected under the passenger footwell. Look for large yellow wires. (Confirm with ECM code 51 which also causes this code) If so the ECM will not receive power and this code will be set. Also, check CCM fuse 5% chance but easy to check. - ECM replacement. Known to solve the problem around 35% of the time (Especially if the ECM has a broken mount and has been rattling around) Replacement ECMs can be found cheap by finding interchange info for other similar GM vehicles. Make sure you swap the EPROM chip into the new matching ECM prior to installing back in the vehicle. - CKT 800 (Tan) Wires and grounds or poor corroded connectors (Usually the problem 35% of the time) - Faulty ignition control module, coils and failed linked computer components 17% (Will throw C41 codes as well) - EPROM replacement, has solved the issue in very rare cases 5% - CCM modules have a near-perfect track record and have almost never needed replacement to solve this issue. The Factory Service Manual 8A Electrical Supplementation has a troubleshooting guide for the CCM to verify proper functionality prior to replacement. 3% (As a last resort after trying everything else) Locations to check for faulty wires: - Under the drivers knee panel (hush cover) Check C68 wire area for steering column or pedal linkage rubbing-pinched and exposing wires tan wires and coming from the ALDL connector itself. - S222 Main CKT800 serial line main branch junction. Behind center of instrument panel behind HVAC unit. Very close to CCM. (Check for corrosion and clean) - Physical wires leading to ECM (Especially if the ECM has a broken mount and has been rattling around) - Wire junction area under the top of dash near right side of defrost vent up by windshield (can get corroded from moisture over time especially with existing heater cores leaks) Unfortunately this requires pulling the upper dash pad to clean and inspect junction wires and connectors
@@MotorAgeMagazine THANK YOU for this thorough explanation. At the moment, I have the dash apart and have been going through looking at wires for connection problems. I don't see any, but it is a maze under there. It kind of impresses me with the technical savvy of the GM Corvette at the time. They really are complex, but it puts me behind the 8 ball without an OBD2 port, which I was hoping that the ALDL port with the right scan tool could help. But flash codes are the best I can hope for at this point. Anyway, I will keep trying. I hope it isn't the ECM, because I just sent it out to be rebuilt and hope they did the job right. The CCM is almost impossible to access and I have very little hope of that even being the cause anyway. I hope to get his fixed and will share my experience then. Again, thank you!
@@peacepoet1947 Thanks for asking. Yes I was. But it is a long story. The lesson learned for me is that it was a combination of the ECM, the MAF sensor, and the fuel injectors. I had to buy a rebuilt ECM (they aren't made anymore). I sent it out to be rebuilt twice, but they messed it up so I went to another company that looked at it and said it was basically falling apart, which is why I had to buy one. But now it is running like a top.
@@moodberry do you know anything about a POM used in the ECM on a 94 GMC? For some reason my distributor is not communicating with it and why I get a code 42. I have DOB1 reader. I had replaced the plugs and wires but while driving to get it smogged the plug wire failed. I went to AutoZone and got another set and put it on. The engine smoothed out nicely. Timing the engine didn't work out. Tightening up the nut changed the timing back to where it was before moving the distributor. Two people suggested replacing the bolt.
Great video! just subscribed as well , So i have a 2015 dodge Durango repaired bad plugs and 2 coils was fine until about 2 weeks after check engine light came on when it started and ran just fine following morning it turned over but wouldn't stay on. Ruined the battery from trying to start it, Went and purchased new battery and its doing the same only now it sometimes gets stuck cranking for about 5-7 seconds but doesn't stay on. checked all fuses and relays error code is loss or failure of communication to ECM/PCM. Any ideas you can lead me to?
I have a question I have 3 codes in my scanner tools thermostat, coolant temperature sensor, and I got this message too ac is not working because of engine hi😢temperature. I replace all the parts its always appears on the dashboard and I can’t erase the code with the scanner tool. What should I do?
I have a 2013 F-150 with the 5.0L and having intermittent issues. While moving or at idle it will suddenly start running rough. When I shut the engine off and wait several seconds before restarting it will run fine. A year ago my water pump went out and caused my vehicle to overheat after that it would run a little odd on rare occasions. Over a month ago we had some heavy rain and I had hit some water that was a little deeper than it looked. And since then had the problem with it running as described above. It's almost like the engine is being shook apart. I took it to the Ford dealership since it's under extended warranty but they said they could find nothing wrong. Could the ECM be telling the PCM there's a problem? Or vice versa? I purchased a dongle and use it. The code that shows the most is P02111 but it will also show body sensors and others on occasion.
Hello,Circuit Intermittent , sometimes when you starter the vehicle check engine going on with VSA, nothing different after update , already replaced the crank shaft , the problem is still , I try to take off the cable from cam shaft sensor and I drive the car. It's nothing gonna be happen no a check engine going on , the pcm has been delay to see I take of the jack from the sensor so what do you think the problem? Thank you.
How would you perform this diagnostic if you have a no start condition? I had a plethora of codes leading me to suspect the PCM is bad on my '05 Grand Cherokee. After attempting several lines of diagnostics, I attempted an OBD-II code scan\health check, which took about 5 minutes, but the moment the test started, my ESP\ECT light came on the vehicle, and three new codes came up for the throttle body circuit. Starting with P2100. The vehicle now will not start, and I hadn't touched anything that would cause this problem.
I have an 09 Chevy Traverse. It's throwing a P0116 code. The shop tried everything they can, but they're still getting readings with multiple temperatures. New ECT module is in, thermostat is not sticking. They recommend taking it to a GM dealership for ECM review. Thoughts?
I have a 2011 camaro 3.6 3 shops have replaced engine harmess throttle body and went thru all.the other sensors checking for bad spots, still getting p2138 code limp mode and now shop says it may be the ecm, is there a way to find out if the ecm is just bad on just that circuit, car has ran fine until this issue
Thanks for the Great Video. I'm a 67 yo Retired Professional Wrench (Audi's are my Specialty). I'm currently dealing with the #3 Coil not Firing (or very weak) on my 2015 Sea Doo GTX iS 260 Limited. I've Swapped Coils, Tested the Wiring to and from the #3 Coil, taken apart the Bosch Motronic ECM & Visually Inspected along with Diode Testing of the MOSFET Coil Drivers / Transistors... Nothing Tests differently while comparing like same Chips. I'm assuming that the #3 MOSFET Chip has Failed under Load. I've ordered 10PCS V3040D 400V, N-Channel Ignition IGBT ISL9V3040D3ST TO-252 Chips hoping that they are compatible? (wasn't able to Match Up #'s on the Original Chips = DE 4 1BE / 07096?), I'm willing to Swap Out all Three (3 Cylinder 1503cc Rotax 4-Tec Supercharged 260 HP) and hope for the Best? Will close be to 3 weeks to receive the Chips. Any Suggestions appreciated. Randy AKA randog311
@randymueller2349 being you are a retired professional Audi Technician, could you please explain to me what is Audi's code P12A2 ? Where do i look in respect to the code, My Q7 was running now its acting really cooky and seems as if it wants to start but doesn't in some tries, then in another will momentarily /briefly start then cut right off. I attempt to step on my accelerator pedal ever so slightly however, there is absolutely no response from pedal unless i actually press it damn near to the floor...for a 2007 Q7 with 3.6L V6 engine. Thank you.
The subscription for this is $50 a month, although this may not seem like a lot, when your getting into the business this is just another added expense. This needs to be closer to around $25-35 a month. The alternative is to organize all the video's related to the particular training or individual part that you are repairing.
Would a bad ecm/pcm still operate the engine but not connect to a code reader? I bought a car recently (you can see it on my channel, 97 mercury cougar) it runs almost good, idles high and surges occasionally, everyrhing i tried cant get a code reader to communicate with the vehicle, even went as far as tracing all the DLC wires to their destination to see that theyre all ok, proper voltages and grounds at the pins themselves, still no communication
I dont have any scan tools and I'm not a mechanic. I had to put my truck in the shop...the guy is the best around. He checked every wire, every sensor, said my o2 sensors were bad, the injectors also and the mass air flow sensor which was new already...I replaced the o2 sensors, the injectors and warranty my mass air flow sensor. It ran decent for a few days ..check engine light eventually came back on and it said mass air flow sensor again...replaced it again and then it said it's still bad and now it runs like crap...idles high, goes into reduce engine mode...the guy said the computer is bad...I cant afford to put it back in the shop, but I found a website that programs a new computer using my VIN for about the same price to just have the truck put in the shop again...going to try this and see....hopefully it does work...my budget is low I cant buy scan tools, have zero idea how to use them anyway
Try www.autopcms.com for help. But keep in mind that if the ECM is bad on your vehicle, something CAUSED it to fail. You have to find and fix the cause or the new ECM won't last long.
@@rapvault98 I just drive it and when it goes to reduce engine power I pull over for a few minutes and then go again until it does it again... I dont have the tools or knowledge to figure it out and the mechanics around here dont seem to either. I bought a gas saver car and will hope it lasts 2 years
@@albertthedogeinstein7983I'm dealing with exact issue. Reduced engine power light. Pull over, turn off, restart and worked fine.... But yesterday it wouldn't restart and it cranks even after I stop turning key, won't start/run. We TRI throttle body bc code p1516 but it's not. Checked a ton of wires and voltage, fine. Taking it in bc it's probably ignition cylinder or this darm Comp ecm
Hi just wondering if anyone knows what I can do to connect with my obd as the mechanic I took it to his scan tool gets power but cannot connect to the car I tried mine when I got home & the same thing happened
A "no start" condition can only be one of three things - lack of compression, lack of fuel, or lack of ignition - including any of the three not happening at the right time. Low compression can usually be heard as the engine cranks over. It will sound like the starter isn't working as hard as it should and there's no resistance when spinning the motor over. Ignition can be easily checked with a simple spark tester, available at any auto parts store. And fuel depends on the system in use - port injected engines usually have a test port or you can disconnect the line to the rail, place it in a clear container, put some eye protection on, and have someone crank the engine over as you watch for fuel out of the line. GDI engines and diesels use a high pressure system that is a little harder to check - you'll need a scan tool to read fuel pressure on these designs. DO NOT attempt to open either system without bleeding the pressure off first! These high pressure systems can HURT you if you don't treat them with respect.
The problem i have is turn key on and your check eng lite does not come on at all .its suppose to come on and go off before you start. Mine doesnt even come on there fore no fuel no stark just turns over
Did you ever figure this out my 03 jeep liberty is doing this and I was told its the fuel sending unit and fuel pump got that replaced then they realized the lack of check engine light at key turn and said it's supposed to do a self check and cycle through go off if it's good and stay on if there's an issue but never comes on to start with and it just cranks but never turns over. Originally was stalling suddenly everytime I stopped at a light and didn't keep foot on gas but then 2 days later just cranks and won't turn over completely to start
You can watch the resistance change as the throttle is opened and closed but you can only catch a glitch in the signal with a scope. A multimeter isn't fast enough.
@@MotorAgeMagazine I used the paper clip method of pulling my OBD I codes and I put the paper clip in the wrong two slots and turned the ignition on. Could this have ruined my ECM 2 weeks later? If I did damage the ECM wouldn't have been immediate? The truck turns over but doesn't start. It has plenty of fuel pressure and it is giving me Codes 15 and 32 1993 Chevy 5.0 1500K Thank you for your time.
@@mperhaps It's possible. But before you condemn the ECM, troubleshoot the two codes first. Both are circuit codes. Start with #15. You'll need an OBD I scan tool so you can view the data PIDs. With the sensor unplugged, you should read -40 degrees or so.
I have found out from my ALLDATA DYI that there is a TSB about lean codes with or without driveability problems. This is on my 05 ford 5.4 . Is it possible or have you ever seen this condition only show itself after so many years ? Is Ford the only one that can re flash the computer ? Can it be sent into a computer exchange with vin #. Is there any reputable companies that do this ?
I would certainly make sure the ECM is up-to-date. You'll need a shop that has the capability to reprogram the ECM in the vehicle. And no, every OEM module can be "flashed" or reprogrammed (with the right equipment and training).
After putting a battery in my car, I had a smoke show when I shut the hood..Now my car is completely dead..How do I diagnose..Hoping it isn't the ecm..
I have a 05 gmc serria an yesterday it stoped shifting from 2nd to third it won't go higher than 2nd an if I leave it over drive it just naturals out an revs up an won't go back in to any gear until I stop sumtines it goes to 1st other times only to 2nd auto zone check engine light said repair pcm wiring an also has po420 p0 430 an po496 I am just looking to see if anyone can tell me where to start
@leroydehne708 I have one for you....2004 chev 5.3 silverado....codes are lean b1,b2..long term pegged @25, short goes to over 35. This is mostly at idle: ..smoked intake: replace valve cover, lower knock plate, intake, all seals. resmoked: no smoke anywhere...even the brake booster and ,evap solenoid tests good. engine vaccum is 18 steady. egr ...All sealed. Pcv valve replaced , still lean codes, checked o2...lazy, replaced upper L &R 02's...still lean codes, checked intake, maf sensor, maf was old orig, replaced maf...still lean codes, checked TB....removed, cleaned, still lean codes, replaced TB. checked compression physicly...all good 170's, replaced spark plugs, replced ig coils, wires, I previously did a Krank sens relearn and it passed...No ecm relearn for tB......still lean codes, replaced crank sens. (engine runs but still could be a lazy krank sens) tried the relearn...now the ecm will not go into relearn between 4-5K rpm's. still lean code.(maybe because it allready passed and the ecm will not redo a relearn..not sure on that) powers and grounds were checked, cleaned double checked. fuel press is good, 58 psi, no drop in 10 min. (filter is on pump in tank) no issue there, replaced 8 orig injectors, still lean codes, Lterm peggs at 25, short is running 20's. This all happens at idle. Go down the road 30,up t0 50 mph: Lterms 20's sTerm running single. So its better. but still sets the ck eng light. Im currently checking the Thottle contrl module. Its intermitant limp mode. replaced Thrott cont mod with known good doner, same issues. Lean codes at idle, This whole truck is full of intermittent gremlins. No vac leaks, no rips in the intake snorkle, scan shows normal rich on 02 at wot. Idle still goes lean B1,B2...after a longer run, idle will stumble, restart engine, runs better. Very strong engine power above idle, Im also thinking this ECM maybe be funky because it wont go into crank relearn...but that could be normal. to be continued. any other ideas?
I've got no clue what you're talking about but I need your help and you sound like an expert. 2011 Chevrolet Traverse 198000km. P0601 came about, I erased it and it came back 1500km later. No driveability issues. Other codes presented P0420. What do I do? What do I tell my mechanic?
The P0601 is an internal ECM error code and will likely require that the ECM be replaced. I would reach out to www.autopcms.com for help. Keep in mind that you need to test the actuators connected to the ECM as well as the power and ground circuits to make sure the new ECM has a chance. As for the P0420 - don't worry about that one until the new ECM has been installed.
My check engine light came on plugged my scanner into the port and showed blank screen figure well my scanner is at fault plugged in a another scanner that scanner said can't communicate!!!🤔? GMC sierra 2500 HD 2004 also the high beam indicator light stay on all the time!!!
Thanks Pete, great video. I see your using the Autel lab scope lately, how do you like it compared to the Pico? I'm looking to upgrade my scan tool, and though I'm a Pico user, I really like the Bluetooth aspect of the autel/scope combination.
Interesting about the Autel scope. What's the cost, how many channels, what's the warranty? Does it come with attenuators, that current tool and connection wires? Using a scan tool to control a device is good, but can you control a device AND monitor it or the result on the same page with the appropriate pids? I used to do that with the I.D.S. we had at work.
Mike - the Autel is a 4-channel scope with possibilities I haven't even gotten to yet - like viewing the scope and scan data at the same time. You'll have to ask Autel for more info, though. Try logging on at www.Autel.com
Hi! Cannot find part # ECC11977U after market Engine Control Module for Chrslyer 2003 Town&Country 3.3LV6 motor car only has 102,000 miles would not do areas out for inspection so brought to a electrical specialist said it needs new ECM, but they don't make so try to get after market and one that is not programmed and he will put in and program just cannot get that part probably will have to junk car by next time for registration FEBRUARY 2024 car drives and works perfect! Would you try ECM that's already Programmed? Or are we taking a chance?
I know this is a long shot , but I have to ask ! 06 Dodge Dakota SLT 3.7 had to replace what they called a multi function control module , it plugs into the fuse box under the hood , wiring harness plugs into it , ok , every light on dashboard is lit up , no wipers turn signals horn radio not sure what else ! It does start ! Hooked scanner up and it says error , no codes ! Was told the pcm is bad and not sending info to scanner , is the pcm and ecm the same thing ? And would it control all of my problems ? Help me
I had an 05 Dodge 65.9 diesel,,, no lights, no cruise, only headlights*, many no functions ,,,,, first got a new fusebox,,,,, then months later I needed that module plugged in on the side u mentioned,,,,, dealer tried 5 modules no good,,,,, rhen rhey got me A module and a new fuse box paired together and that worked**
What about an ecm that has been used as a jackstand on my tractor.??? I'll run some tests on it before I buy a new one.nect time I'm just going to use a big log for jackstand instead!!!
Hi love your videos very informative! Just a quick question I have an 86 ford OBD1 EEC- IV system which doesn’t communicate with any scanners so I can’t see any of the perimeters, do you know if there’s a module that can be connected to between the ECM and the scanner that maybe be able to read some or all of the perimeters? I doubt it but had to ask 😀 What I do is back probe the sensor I’m checking at the ECM using my AES Wave uscope…. Tnx Leor
This might be worth the investment. It does OBD II and OBD I, allowing access to data stream and vehicle self tests as well as reading codes (instead of counting flashes). www.tooldiscounter.com/product/actron-elite-obd-i-and-ii-autoscanner-kit-actcp9690
@@MotorAgeMagazine hi Tnx for your quick reply but I already have a snapon mt2500 scanner AKA the brick but can’t use it to read perimeters like fuel trims and other perimeters…. Too bad
Perhaps - but start with fundamental troubleshooting. Does it turn over normally, indicating some compression in the engine? Does it have a good strong spark? Is it getting fuel?
Car was stuck at work .I got a new battery it wouldn't start.i jumped with a jump box it started up with gas in it.when I turned the car off it won't start at all.obd scanner say fuel volume regulator circuit open.light and radio is on car won't even try to start
@@stephanmoney7493 The code is an electrical issue that could be in the ECM or the Fuel Control Valve itself. It could also be something as simple as an unplugged connector or broken wire. You'll need a scan tool that can read the data, a wiring diagram, and a voltmeter/ohmmeter to diagnose and correct the problem.
Dont get me wrong what you have here is knowledge but I dont have the tools you have nor the skills, but my ECM is three plugs and one bolt so if I can but a used one for $100 bucks or so...if I simply take old out put in new and it solved problem ya. If not I am out 100 bucks but I would have to pay for diagnoses and tow truck .... buying ecm if cheap would be pretty quick would it not?
On late model vehicles, you can't simply install a used one. The VINs have to be matched and often the new module has to be programmed to the application.
I'd like to know how I can fool the ECU on my Honda Accord from a knock sensor readout? It's a cheap part that keeps tripping the light and a code and I keep clearing the DTC. The original one went toast and so I just purchased a cheap one to get me by for now. I hate the idea of spending over $200 bucks for a OEM sensor... any ideas?... besides an expensive part purchase? Btw, the prices on these knock sensors are all over the board, hard to know which one to get besides a OEM.
I'm not sure if plugging in a resistor matching the sensor's resistance will work or not - it depends on how the ECM tests the circuit and whether or not there is any kind of rationality test associated with it. As for parts, see if Duralast offers one for your Honda.
@@MotorAgeMagazine thanks, not sure what to do? It's looking like I'll have to go OEM. From my research, Honda vehicles are very particular on this part, aftermarket parts don't appear to work right. You can test these on a automotive scope for a specific sine wave, but I have no idea what's acceptable or what isn't, what the ECU rejects or not. It's like a top secret recipe... damn Hondas.
@@garyr7027 What is the code you are trying to address? Perhaps it isn't the sensor, but a circuit issue. And you can find "known good" waveforms on a variety of sites, like www.picoauto.com.
@@MotorAgeMagazine P0325 is the code, but I didn't get that code at first. My car started running really bad, no CEL and my code reader couldn't pull a code. It wasn't until I bought a scan tool that I got a code. Once I got that code, I got under the car to pull the connector off the knock sensor, and the sensor fell apart, then I got the CEL. So I replaced the sensor with a cheaper brand and it's been a issue since. Now every 400 to 500 miles or so the CEL will trip, the car runs rough, until I clear the code with my scan tool, and it'll run fine again until the CEL comes back on. The original sensor never did trip the CEL until I pulled the connector and I don't see anything wrong with the wire going too it, and that's the part that doesn't make sense to me.
@@garyr7027 Your comment that the car was "running really bad" has me intrigued. The knock sensor will not cause any drivability issues but is used to report to the ECM when any instance of detonation or preignition occurs. Is this code reoccurring and is there any other code stored or pending? (Check Mode $07 and Mode $03 on your generic scan tool).
I feel I should clarify some terms in regards to ECM (PCM) module design (USA based PCM hardware and software development). This may be looked at as industry jargon, but it really makes sense once you understand the complete PCM development cycle.
The PCM control algorithms are called strategy. PCM code execution is done using a multitasking priority based preemptive real-time operating system, meaning processing is done concurrently on several different control systems or tasks. The processing is not parallel (because the processor usually only has one execution core) but switched between the tasks at a rate which satisfies the update requirements of the function(s), making it look as though several systems are being managed at once. Also, the PCM RTOS is a hybrid, multi-domain operating system, having algorithms execute according to time (like in seconds, or time domain) or crank position (degree rotational, or crank domain, this is why PCM execution loading increases with increasing engine RPM).
A strategy can be generic across an engine family but be unique in terms of engine specifics. This list of constants used by the strategy is called a calibration. For example, you may have one engine in a family which is of a larger displacement, so the constant "map", or calibration, would be unique to this engine for volumetric efficiency or spark advance.
Strategy can be generic, but calibrations are specific.
The video is a bit strange if you assume the PCM is post OBD-II, and includes two way control using a scan tool, which, as most experienced diagnostic techs know, for non-oem tools is hit or miss like the Autel scan tool in the video, but many times either is useful enough to diagnose a problem, or displays a good number of PIDs (Parameter Identifiers, basically PCM variables) to allow a starting point for troubleshooting.
The first step in understanding if you need to replace a post OBD-II PCM is to talk to it through a scan tool. There are a good many basic P0 OBD-II codes which pertain directly to PCM operation, so if you have stored or pending codes these will give an indication of the problem. The most effective diagnostic for understanding if you need a PCM replacement is asking the PCM.
From a circuit standpoint a great many PCMs fail due to high temperatures in or around a power output stage (transistor). Other problems are related to the PCMs age, like leaking Aluminum Electrolytic capacitors (tend to fail with age) which can make a PCM have intermittent problems.
This is really useful comment man, thank you for posting it.
I'll stick with my '73 Dodge with points, condenser and rotor!!
@@allenbeck7321 so is this some weird hobby of yours to comment on the advancement of auto technology with you keeping an antique on the road😅
@alexanderthegrape5370 no just came across this video that shows just how ignorant I am. Still have a house phone too!!!
Dodge you feel superior? Let this man work
The average Home Mechanic is never going to be able to understand this information in this amount of detail. I am guessing that all of the Test Equipment used to do this work costs a Fortune. Our Vehicle Technologies are Way out of control if you ask me. No wonder the Average Person cannot afford to purchase a new vehicle. I just cannot Wrap my mind around the fact that a Basic Large Pick Up Truck for instance may cost anywhere from $40,000 to $90,000. We must remember this is only Transportation that drops off in value as soon as you drive it off of the lot. For this kind of Money I woukd invest it in a House that may increase in value. If I was in the Market for a Truck for instance I would find an older model that is in good shape for a decent price. If I had to wind up putting $5,000 to $10,000 in it to use it reliably for several years it would be worth it.
You're reading my mind. Learning about PCMs right now because my beloved '98 Wrangler is dead because I dared splice into the wiring to install an new aftermarket gauge cluster and OH BOY am I regretting it. I fear the 'puter brayn in my Jeep is dead and am spending countless hours reasearching and parts buying and testing to only suffer increasing frustration and a reluctance to ever do my own work again. This experience makes me NOT want to buy a new car, but to buy an OLD car, one that I can fix. Everyday I hear people complaining about their (modern) cars. It seems this choice made by the auto industry to purposely complicate things is one made only of pure greed. The house I grew up in cost less than a modern car. Capitalism out of control.
Same bro. I agree 100%
It’s not so much the technology, because everything has it, it is because no one pays attention to our government and our tax dollars. Your dollars are worthless trash, they keep printing money, ( about 1 trillion every hundred days) government and big corporations are in bed together paying each other with tax dollars. You get higher costs of everything.
I agree with I just told my friend the same thing last night. If I have to spend up to 10,000 to keep my truck road worthy then so be it. I'm not paying 70,000 for a new truck now a days.
Mechanics fix vehicles, not soccer dad's or dentists. It takes a lifetime in the repair field to become well versed in auto repair. People need to stop trying to work on their own stuff, it ends up making the repair much more involved because people wanna try save a few bucks. Would you go to McDonald's and expect to find someone that can do your brain surgery?
They should make a law that if a car company makes a car with a computer, if that car has any problems that evolves the computer that they should have to fix it for free if they're going to sell them.
Love the last comment he's absolutely correct this guy's too good to make videos😮
The best teacher imo.
BRILLIANT, BRILLIANT, BRILLIANT, sorry for repeating myself but absolutely brilliant video. I know i am going to make a glutten of myself by the repeated watching of this video over and, over. Many thanks, thumbs up and subscribed.
Thank you for the kind words - I'm glad you found this video helpful. And welcome to the channel!
I have found in about 50% of the cases where the flow chart call for the ecm to be replaced that pin fit is the cause. You mentioned corrosion, but GM has several TSB's concerning incorrect pin fit caused by vibration and incorrect testing methods. In addition, some manufacturers have known issues with internal faults, others not. I ALWAYS find the cause before replacement. Case in point, Ford 3.0 ignition coils causing the drivers in the ecm to fail....
sometimes you can correct a problem just by unplugging the ECM and then reconnecting, making certain you hear that "click" when you reconnect the ECM.
1qq2²
@@steveolive9991 I have a 2008 Honda Civic Lx. All 4 cyl were replaced on tune up. I got a code saying all 4 are misfiring, drain bad fuel. Makes no sense.
My uncle told me (mechanic for 25 years) that bad fuel wouldn't be an issue in Florida as heat would evaporate any water. I replaced my plugs & they looked okay.
Still having issues. Don't know what to do now. Change the ECM? I mass air flow sensor is brand new too.
What else could it be?
@@steveolive9991 Hello, should the battery be disconected when disconecting the ECM? Thank you for reply.
@@etiennebisset5642 please let me know
Good Morning Pete Meier motor age Take care and have a great day Pete Meier
Tutorial great thank you 👏 👌 👍
From Nick Ayivor from London England UK 🇬🇧
I was replacing my Crankshaft sensor and it broke off inside where the magnet goes l pulled on it hammered it back up in the and now my new crankshaft sensor don't fit it won't go all the way in do you think l have to replace the wheel?
"the ecm is the most expensive fuse on the car" i'm going through a rough time with my subaru right now, and that made me feel much better, at least for a moment
Did the ecm fix the problem???
@@ricksmith2476 nope. i finally broke down and called a friend who runs a shop, saying i thought it was the ecm. he said, paraphrasing: "it's the most complex component, so people default to thinking it's the culprit" turned out, when i checked the fuses in my 96 subaru legacy (my first step, btw!), i missed one: buddy brought up his wiring diagrams, and had a hunch it was fuse 15. which it was. thank god.
Thanks I will check my fuses again before I buy ecm thanks for the info I have a 94 suburban
I have a problem that's telling me the p0017 and the poo 04330 is coming up all the time even with new O2 sensors new cam sensors new crank sensors could it possibly be the ECM 2:34 2:35 2:36 2:37
Please reply
Excellent video. Thank you, sir.
Just bought my first autel ms906 pro absolutely love it
WOW! Now I know for sure that I know absolutely nothing❗️ 🤓 Thank you… I found it inspirational and even understood < 0.095%. But really you were very clear, and not rushed at all.
I’ve got a P0483 along with P0606 on 2006 Ram2500 5.9l. No idea what to do but I have cleaned all obvious grounds (just got it and it has 208k mi’s on it. One thing I have no idea about is how to find the grounds inside the wiring connectors. I do have the Dodge exhaustive wiring diagrams but am super confused about how to locate for exmpl, the fan clutch control in the Drive-Fan Radiator module, as it runs between that and the ECM (but I have the wiring diagram of that). The reason I’m looking at that is: I think there could be a connection that needs cleaning and so hopefully the ECM is really ok.
Any help is appreciated!
Thanks again for your efforts to help us❗️❗️
Art in FL
Thanks for sharing Pete, Happy New Year🎆
How are you sir i have a 2006 silverado i parked the truck trhee weeks ago running fine today I want to start the engine the battery was dead it was an old battery so i went to buy a new one after installing the battery truck doesn't start i can hear the fuel pump running when i open the ignition switch but won't start door locks doesn't work neither nor dash clusters base on ur experience u think computer is bad???????
Mine had all of the issues listed. Just ordered my new ecm so it will pass inspection ✌🏻
Where's a good place order ecm?? My 05 dodge ram 5.7 hemi won't start
NOW THIS WAS TRULY A TECH HELPFUL VIDEO ,,, PLEASE I HOPE TO SEE MORE HELPFUL VIDEOS LIKE THIS ONE NOT LIKE OTHERS THAT SEEM TO BE MORE LIKE COMMERCIALS FOR DIFFERENT PRODUCTS I KNOW WE ALL NEED ARE SPONSORS BUT AT LEAST SEPARATE THEM FROM THE TRUE TECH HELP VIDEOS , THANKS PET!!!!!!!!!!!!!
Noticed you video very helpfull, on a gmc acadia 3.6, ive had multiple codes and replaced many things but still car goes to limp mode and stalls will no xheck engine light do you think it could bad ecm? I got good, fuel, good air, good power , but problem is still there
Did u figure it out?
Ecu is a very expensive fuse. Great phrase!!
Motor age this video is informative, but my problem is a little tricky. I have a 2003 chevy tahoe Z71 5.3L. Im using my snap-on solus ultra scanner. I have communication with the ecm/pcm. The vehicle starts fairly consistently, but it has started to develop an issue where it won't turn over at all. All the fuses are intact. I haven't found any obvious wiring issues. All the relays cycle as expected. The ecm/pcm just started showing an error code for a communication fault. It does this when attempting to cold start or after the engine is at operating temperature (the few time i was able to start it). I have replaced the ignition switch due to wear and it ran for approximately 3 weeks before the no crank problem returned. When it would crank I was able to read all available pids. I can read the ones that are not dependent on the engine running and haven't been able to pin the issue down. This has been an intermittent issue (about once every 2-3 months) until recently (every other day). I pulled the starter and bench tested it to eliminate it from the check list. I haven't found and fouled or damaged ground straps. Everything else seems to be in good repair at this point. Any additional insight would be greatly appreciated as I'm at a loss and really cannot afford to replace the ecm/pcm at this time.
I'd check the fuses box on the left side underhood the data lines and other main circuit run though it and they known to get corroded.
Thanks for the mechanic channel education
What about when you haven't been able to to turn the engine on in a couple weeks hard to diagnose the problem after my battery died and erased my codes.. problem is that I'm not hearing the fuel pump engage fuses and relays seem to be o.k...... so I'm thinking it could be the ecm but I did a visual inspection after taking it out and the circuit board is super clean!!!!!! what should I check next......
same boat
did you ever get it figured out ? @marcisohm187
Thank you Pete.
Thanx for information about circuit and economics having poor performance and fuel consumption
3.7 2008 jeep commander New plugs are oem and clean pm service
Over the past few months fuel Consumption has steadily declined
Thanx again for your Video
Have a Great Day 👍
Have you looked at fuel trims? How is the power? Any other drivability concerns or just low fuel economy?
OK look o have a gmc 05 pick up an the trans just started this it won't shift from 2nd to 3rd it just revs up an I went to auto zone an hooked up to read codes an one Said repair wires going to ecm where should I look also is there any way to change this to see if I can make it work so I can drive the truck
Another very informative video. Only recently found this channel and based on the content you should have a subscriber count in the millions.
From your mouth to UA-cam's ears...🙂
@@MotorAgeMagazine my engine had a 42 trouble code. No check engine light is on. I drained the system to try to reboot the ECM. Not sure where to start looking for the problem. I only have a 12 volt probe and a multimeter. Any advice if I need to replace the ECM? Been watching videos for days but haven't found the information that I need.
@@peacepoet1947 What year, make, model and engine do you have? Let's start there...
@@MotorAgeMagazine 94 GMC Sierra C300 with a 7.4 engine. Had code 42 and did a system drain to see if I could reboot the ECM. Code has disappeared and I will drive her in a bit to see if will give me any codes. The engine will rev up in park but in gear the timing doesn't seem to advance.
@@MotorAgeMagazine did a short idle to the Smart and Final for some whole milk to take with the aspirin I need to take for the back and leg pain.
I don't have any scope. Got a 12 probe that has a ground lead for detecting current. I also have a multimeter. I got the code 42 on my 94 GMC Sierra C3500.
HELP I bought the book.
Do you have any recommendations for a 2002 dodge PCM repair its not communicating with the cam sensor no crank sensor on this model I suspect weak solder connections
I got My thermostat, Cooling fan, And Spark plugs changed.. Engine sounds good again But Rpms fluctuate and car jerks.. Also It is overheating way more than it was before I changed Thermostat and cooling fan. Was told my ECM/ECU needs to be changed on my 2007 Chevy cobalt... Not sure what to do spent 3200 On it and Now that..
Hey , I see your situation happened a year ago but do you remember how it turned out ? We have the exact same car with 302,000 mi. Things are happening now at that mileage but this one is harder to diagnose . I am a mechanic .
Just decided not to worry about it, Car Has 270k Kilometers and still runs, with problems of course lol.
I can remember when electronics first came out on automobiles .... It pushed alot of machanic s out of business simply because they could not Comprehend the basics of electronics in which through them out in lelf field.... It pays to be educated .
How much for the computer reading tech? And how much for the ecm when it is the problem? Near end of season work I’m really looking for cheap solutions
Good to see you, Pete. Thank you and Happy New Year.
Does anyone know if i can use a used ecm from a different car but the same make modle, year, engine, etc? I have a 09 corolla s and have a ecm problem. Thanks.
I need you to fix my Durango 07..i replaced all the sensors..it runs great until u try to restart vehicle..then stalls..
Replaced ignition switch, cam sensor ,crank, map, im tempted to replace pcm are fuse box
I can't afford a computer scan tool but I do have a multimeter, my 99 astro van is blowing the ecm1 and I need to fix it what video do you recomend or is it hopeless
You know your stuff! But what do I do if I have an OBD 1 port on an older car? I can't seem to find the right scan tool for my car (1992 Corvette) The data is not very deep. Without a tool, the best I can do is use the codes that come on the dash by jumping two ports on the OBD with a paper clip. In my case, I get a communications error (C41) between the ECM and the BCM. Not much help there, so what can I do?
There are DIY versions of the professional service information systems I use that you may find helpful. Here's some info I found that also might be useful:
Module 1 - CCM Code 41 - Communication Error (CODE 41H History 41C Current)
Problem - Central Control Module (CCM) serial communication failure
The CCM requires constant encrypted data communication from the ECM at all times. The CCM communicates in a master-slave configuration, the CCM is assigned as the master and constantly polls injector and data from the ECM before startup in order for the vehicle to run and insure the VATS (Vehicle Anti-Theft System) hasn`t been bypassed. It also communicates with various other modules on the serial line reducing the number of wires required between modules.(early Canbus).
This is not to be confused with ECM error code E41 (Electronic Spark Control Circuit Open) when reading ECM codes. If ECM codes (module 4) come up ERR on the LCD cluster you can scan or jump the ECM directly from the diagnostics port A,B to pull codes directly from the Check Engine Light.
The C41, H41 CCM issue is mainly due to a defective ECM under the hood or open or short to ground of any of the CKT 800 (Tan) serial data communication wires and grounds between the CCM to ECM and other major computer modules behind the instrument panel. This problem can present itself on running and non-running cars depending on severity. A no start condition is typically the result from a complete ECM failure. The CCM shares serial wires and branches them from S222 behind the IP. An open or cut serial wire in the system will disable that specific module where a short will take out the entire chain.
HERE IS THE INSPECTION ORDER TO THESE TARGET AREAS AND SUCCESSFUL FIXES TO THIS ISSUE:
- Make sure the AIR BAG fuse is OK and I/P to DERM harness connector isn’t disconnected under the passenger footwell. Look for large yellow wires. (Confirm with ECM code 51 which also causes this code) If so the ECM will not receive power and this code will be set.
Also, check CCM fuse 5% chance but easy to check.
- ECM replacement. Known to solve the problem around 35% of the time (Especially if the ECM has a broken mount and has been rattling around) Replacement ECMs can be found cheap by finding interchange info for other similar GM vehicles. Make sure you swap the EPROM chip into the new matching ECM prior to installing back in the vehicle.
- CKT 800 (Tan) Wires and grounds or poor corroded connectors (Usually the problem 35% of the time)
- Faulty ignition control module, coils and failed linked computer components 17% (Will throw C41 codes as well)
- EPROM replacement, has solved the issue in very rare cases 5%
- CCM modules have a near-perfect track record and have almost never needed replacement to solve this issue. The Factory Service Manual 8A Electrical Supplementation has a troubleshooting guide for the CCM to verify proper functionality prior to replacement. 3% (As a last resort after trying everything else)
Locations to check for faulty wires:
- Under the drivers knee panel (hush cover) Check C68 wire area for steering column or pedal linkage rubbing-pinched and exposing wires tan wires and coming from the ALDL connector itself.
- S222 Main CKT800 serial line main branch junction. Behind center of instrument panel behind HVAC unit. Very close to CCM. (Check for corrosion and clean)
- Physical wires leading to ECM (Especially if the ECM has a broken mount and has been rattling around)
- Wire junction area under the top of dash near right side of defrost vent up by windshield (can get corroded from moisture over time especially with existing heater cores leaks) Unfortunately this requires pulling the upper dash pad to clean and inspect junction wires and connectors
@@MotorAgeMagazine THANK YOU for this thorough explanation. At the moment, I have the dash apart and have been going through looking at wires for connection problems. I don't see any, but it is a maze under there. It kind of impresses me with the technical savvy of the GM Corvette at the time. They really are complex, but it puts me behind the 8 ball without an OBD2 port, which I was hoping that the ALDL port with the right scan tool could help. But flash codes are the best I can hope for at this point.
Anyway, I will keep trying. I hope it isn't the ECM, because I just sent it out to be rebuilt and hope they did the job right. The CCM is almost impossible to access and I have very little hope of that even being the cause anyway. I hope to get his fixed and will share my experience then. Again, thank you!
@@moodberry were you able to get the work done and fix what went wrong?
@@peacepoet1947 Thanks for asking. Yes I was. But it is a long story. The lesson learned for me is that it was a combination of the ECM, the MAF sensor, and the fuel injectors. I had to buy a rebuilt ECM (they aren't made anymore). I sent it out to be rebuilt twice, but they messed it up so I went to another company that looked at it and said it was basically falling apart, which is why I had to buy one. But now it is running like a top.
@@moodberry do you know anything about a POM used in the ECM on a 94 GMC? For some reason my distributor is not communicating with it and why I get a code 42. I have DOB1 reader. I had replaced the plugs and wires but while driving to get it smogged the plug wire failed. I went to AutoZone and got another set and put it on. The engine smoothed out nicely. Timing the engine didn't work out. Tightening up the nut changed the timing back to where it was before moving the distributor. Two people suggested replacing the bolt.
Great video! just subscribed as well , So i have a 2015 dodge Durango repaired bad plugs and 2 coils was fine until about 2 weeks after check engine light came on when it started and ran just fine following morning it turned over but wouldn't stay on. Ruined the battery from trying to start it, Went and purchased new battery and its doing the same only now it sometimes gets stuck cranking for about 5-7 seconds but doesn't stay on. checked all fuses and relays error code is loss or failure of communication to ECM/PCM. Any ideas you can lead me to?
Same issue on my 2015 tiguan! Error codes p0507 and now p12a4, which is maker specific, pointing to the ecu. Any answers to your situation yet?
I have a question I have 3 codes in my scanner tools thermostat, coolant temperature sensor, and I got this message too ac is not working because of engine hi😢temperature. I replace all the parts its always appears on the dashboard and I can’t erase the code with the scanner tool. What should I do?
Got the same problem. Gonna replace the ecm and cross my fingers
I have a 2013 F-150 with the 5.0L and having intermittent issues. While moving or at idle it will suddenly start running rough. When I shut the engine off and wait several seconds before restarting it will run fine. A year ago my water pump went out and caused my vehicle to overheat after that it would run a little odd on rare occasions. Over a month ago we had some heavy rain and I had hit some water that was a little deeper than it looked. And since then had the problem with it running as described above. It's almost like the engine is being shook apart. I took it to the Ford dealership since it's under extended warranty but they said they could find nothing wrong. Could the ECM be telling the PCM there's a problem? Or vice versa? I purchased a dongle and use it. The code that shows the most is P02111 but it will also show body sensors and others on occasion.
Hello,Circuit Intermittent , sometimes when you starter the vehicle check engine going on with VSA, nothing different after update , already replaced the crank shaft , the problem is still , I try to take off the cable from cam shaft sensor and I drive the car. It's nothing gonna be happen no a check engine going on , the pcm has been delay to see I take of the jack from the sensor so what do you think the problem? Thank you.
How would you perform this diagnostic if you have a no start condition? I had a plethora of codes leading me to suspect the PCM is bad on my '05 Grand Cherokee. After attempting several lines of diagnostics, I attempted an OBD-II code scan\health check, which took about 5 minutes, but the moment the test started, my ESP\ECT light came on the vehicle, and three new codes came up for the throttle body circuit. Starting with P2100. The vehicle now will not start, and I hadn't touched anything that would cause this problem.
I have an 09 Chevy Traverse. It's throwing a P0116 code. The shop tried everything they can, but they're still getting readings with multiple temperatures. New ECT module is in, thermostat is not sticking. They recommend taking it to a GM dealership for ECM review. Thoughts?
I have a 2011 camaro 3.6 3 shops have replaced engine harmess throttle body and went thru all.the other sensors checking for bad spots, still getting p2138 code limp mode and now shop says it may be the ecm, is there a way to find out if the ecm is just bad on just that circuit, car has ran fine until this issue
What was the issue?
Thanks for the Great Video. I'm a 67 yo Retired Professional Wrench (Audi's are my Specialty). I'm currently dealing with the #3 Coil not Firing (or very weak) on my 2015 Sea Doo GTX iS 260 Limited. I've Swapped Coils, Tested the Wiring to and from the #3 Coil, taken apart the Bosch Motronic ECM & Visually Inspected along with Diode Testing of the MOSFET Coil Drivers / Transistors... Nothing Tests differently while comparing like same Chips. I'm assuming that the #3 MOSFET Chip has Failed under Load. I've ordered 10PCS V3040D 400V, N-Channel Ignition IGBT ISL9V3040D3ST TO-252 Chips hoping that they are compatible? (wasn't able to Match Up #'s on the Original Chips = DE 4 1BE / 07096?), I'm willing to Swap Out all Three (3 Cylinder 1503cc Rotax 4-Tec Supercharged 260 HP) and hope for the Best? Will close be to 3 weeks to receive the Chips. Any Suggestions appreciated. Randy AKA randog311
@randymueller2349 being you are a retired professional Audi Technician, could you please explain to me what is Audi's code P12A2 ? Where do i look in respect to the code, My Q7 was running now its acting really cooky and seems as if it wants to start but doesn't in some tries, then in another will momentarily /briefly start then cut right off. I attempt to step on my accelerator pedal ever so slightly however, there is absolutely no response from pedal unless i actually press it damn near to the floor...for a 2007 Q7 with 3.6L V6 engine. Thank you.
Where do they find the wiring diagrams?
I HAVE a 2003 Caravan and a Launch 129 E code reader, but it was telling me the PCM isnt equipped
I mean outside the ads no notes. As for the ads, i cant fault a guy for profiting off of his knowledge, especially if theyre giving it away.
Do you have a recommendation for a low amperage clamp that plugs into a voltmeter?
I've used this one for years...www.aeswave.com/Current-Probe-Low-range-with-Banana-Plugs-p9501.html
@@MotorAgeMagazine Thanks this helps. Purchased KAIWEETS Digital Clamp Meter and this works great above 60 amps.
Using Diag from my think car with phone. DIY option for OBD data works great.
What model Autel are you using sir.
The subscription for this is $50 a month, although this may not seem like a lot,
when your getting into the business this is just another added expense. This needs to be
closer to around $25-35 a month. The alternative is to organize all the video's related
to the particular training or individual part that you are repairing.
Does this Autel scope feature only five vertical divisions or would it be 2V/div? (around 5.46)
Good catch! The sweep is actually 40v, running across 10 divisions of 4v each (from -20v to +20v).
Would a bad ecm/pcm still operate the engine but not connect to a code reader? I bought a car recently (you can see it on my channel, 97 mercury cougar) it runs almost good, idles high and surges occasionally, everyrhing i tried cant get a code reader to communicate with the vehicle, even went as far as tracing all the DLC wires to their destination to see that theyre all ok, proper voltages and grounds at the pins themselves, still no communication
Yes, but more than likely just a blown fuse
I dont have any scan tools and I'm not a mechanic. I had to put my truck in the shop...the guy is the best around. He checked every wire, every sensor, said my o2 sensors were bad, the injectors also and the mass air flow sensor which was new already...I replaced the o2 sensors, the injectors and warranty my mass air flow sensor. It ran decent for a few days
..check engine light eventually came back on and it said mass air flow sensor again...replaced it again and then it said it's still bad and now it runs like crap...idles high, goes into reduce engine mode...the guy said the computer is bad...I cant afford to put it back in the shop, but I found a website that programs a new computer using my VIN for about the same price to just have the truck put in the shop again...going to try this and see....hopefully it does work...my budget is low I cant buy scan tools, have zero idea how to use them anyway
Try www.autopcms.com for help. But keep in mind that if the ECM is bad on your vehicle, something CAUSED it to fail. You have to find and fix the cause or the new ECM won't last long.
How did it go???
@@rapvault98 I just drive it and when it goes to reduce engine power I pull over for a few minutes and then go again until it does it again...
I dont have the tools or knowledge to figure it out and the mechanics around here dont seem to either.
I bought a gas saver car and will hope it lasts 2 years
I18 at auto zone
@@albertthedogeinstein7983I'm dealing with exact issue. Reduced engine power light. Pull over, turn off, restart and worked fine.... But yesterday it wouldn't restart and it cranks even after I stop turning key, won't start/run. We TRI throttle body bc code p1516 but it's not. Checked a ton of wires and voltage, fine. Taking it in bc it's probably ignition cylinder or this darm Comp ecm
Hi just wondering if anyone knows what I can do to connect with my obd as the mechanic I took it to his scan tool gets power but cannot connect to the car I tried mine when I got home & the same thing happened
thank you for this good imformative video sir.
Is it possible to disable electronic display & use only essential (analogue) instruments?
What kind of vehicle?
My 2014 RAM 1500 Hemi is burning fuse, and ignition coil pack constantly, after so many wiring searches for ground I’m waiting for new ECM from eBay
what do you do when your vehicle wont start up? Thats what we trying to figure out in the first place so we can test it!
A "no start" condition can only be one of three things - lack of compression, lack of fuel, or lack of ignition - including any of the three not happening at the right time. Low compression can usually be heard as the engine cranks over. It will sound like the starter isn't working as hard as it should and there's no resistance when spinning the motor over. Ignition can be easily checked with a simple spark tester, available at any auto parts store. And fuel depends on the system in use - port injected engines usually have a test port or you can disconnect the line to the rail, place it in a clear container, put some eye protection on, and have someone crank the engine over as you watch for fuel out of the line. GDI engines and diesels use a high pressure system that is a little harder to check - you'll need a scan tool to read fuel pressure on these designs. DO NOT attempt to open either system without bleeding the pressure off first! These high pressure systems can HURT you if you don't treat them with respect.
The problem i have is turn key on and your check eng lite does not come on at all .its suppose to come on and go off before you start. Mine doesnt even come on there fore no fuel no stark just turns over
Did you ever figure this out my 03 jeep liberty is doing this and I was told its the fuel sending unit and fuel pump got that replaced then they realized the lack of check engine light at key turn and said it's supposed to do a self check and cycle through go off if it's good and stay on if there's an issue but never comes on to start with and it just cranks but never turns over. Originally was stalling suddenly everytime I stopped at a light and didn't keep foot on gas but then 2 days later just cranks and won't turn over completely to start
Thanks in advance ,how can I test for example the TPS connector with a multimeter?
You can watch the resistance change as the throttle is opened and closed but you can only catch a glitch in the signal with a scope. A multimeter isn't fast enough.
@@MotorAgeMagazine I used the paper clip method of pulling my OBD I codes and I put the paper clip in the wrong two slots and turned the ignition on. Could this have ruined my ECM 2 weeks later? If I did damage the ECM wouldn't have been immediate? The truck turns over but doesn't start. It has plenty of fuel pressure and it is giving me Codes 15 and 32 1993 Chevy 5.0 1500K Thank you for your time.
@@mperhaps It's possible. But before you condemn the ECM, troubleshoot the two codes first. Both are circuit codes. Start with #15. You'll need an OBD I scan tool so you can view the data PIDs. With the sensor unplugged, you should read -40 degrees or so.
I have found out from my ALLDATA DYI that there is a TSB about lean codes with or without driveability problems. This is on my 05 ford 5.4 . Is it possible or have you ever seen this condition only show itself after so many years ? Is Ford the only one that can re flash the computer ? Can it be sent into a computer exchange with vin #. Is there any reputable companies that do this ?
I would certainly make sure the ECM is up-to-date. You'll need a shop that has the capability to reprogram the ECM in the vehicle. And no, every OEM module can be "flashed" or reprogrammed (with the right equipment and training).
Were you able to solve the problem with your Ford?
@@peacepoet1947 I want to know the same thing. I have a 1999 f350. Diesel. Powerstroke.
@@mariefeely972 on the communication between the distributor and the POM inside the ECM?
After putting a battery in my car, I had a smoke show when I shut the hood..Now my car is completely dead..How do I diagnose..Hoping it isn't the ecm..
Where would a guy get ecm pin layout? 1998 ram 2500 cummins, thanks!!
Both Alldata and Mitchell offer DIY service information. Google 'em and subscribe for your vehicle to access everything you need at a reasonable cost.
I have a 05 gmc serria an yesterday it stoped shifting from 2nd to third it won't go higher than 2nd an if I leave it over drive it just naturals out an revs up an won't go back in to any gear until I stop sumtines it goes to 1st other times only to 2nd auto zone check engine light said repair pcm wiring an also has po420 p0 430 an po496 I am just looking to see if anyone can tell me where to start
Do you have access to a scan tool with enhanced capability for GM?
@leroydehne708
I have one for you....2004 chev 5.3 silverado....codes are lean b1,b2..long term pegged @25, short goes to over 35. This is mostly at idle: ..smoked intake: replace valve cover, lower knock plate, intake, all seals. resmoked: no smoke anywhere...even the brake booster and ,evap solenoid tests good. engine vaccum is 18 steady. egr ...All sealed. Pcv valve replaced , still lean codes, checked o2...lazy, replaced upper L &R 02's...still lean codes, checked intake, maf sensor, maf was old orig, replaced maf...still lean codes, checked TB....removed, cleaned, still lean codes, replaced TB. checked compression physicly...all good 170's, replaced spark plugs, replced ig coils, wires, I previously did a Krank sens relearn and it passed...No ecm relearn for tB......still lean codes, replaced crank sens. (engine runs but still could be a lazy krank sens) tried the relearn...now the ecm will not go into relearn between 4-5K rpm's. still lean code.(maybe because it allready passed and the ecm will not redo a relearn..not sure on that) powers and grounds were checked, cleaned double checked. fuel press is good, 58 psi, no drop in 10 min. (filter is on pump in tank) no issue there, replaced 8 orig injectors, still lean codes, Lterm peggs at 25, short is running 20's. This all happens at idle. Go down the road 30,up t0 50 mph: Lterms 20's sTerm running single. So its better. but still sets the ck eng light. Im currently checking the Thottle contrl module. Its intermitant limp mode. replaced Thrott cont mod with known good doner, same issues. Lean codes at idle, This whole truck is full of intermittent gremlins. No vac leaks, no rips in the intake snorkle, scan shows normal rich on 02 at wot. Idle still goes lean B1,B2...after a longer run, idle will stumble, restart engine, runs better. Very strong engine power above idle, Im also thinking this ECM maybe be funky because it wont go into crank relearn...but that could be normal. to be continued. any other ideas?
I've got no clue what you're talking about but I need your help and you sound like an expert. 2011 Chevrolet Traverse 198000km. P0601 came about, I erased it and it came back 1500km later. No driveability issues. Other codes presented P0420. What do I do? What do I tell my mechanic?
The P0601 is an internal ECM error code and will likely require that the ECM be replaced. I would reach out to www.autopcms.com for help. Keep in mind that you need to test the actuators connected to the ECM as well as the power and ground circuits to make sure the new ECM has a chance. As for the P0420 - don't worry about that one until the new ECM has been installed.
Where's that ecm/ecu located?
I have a 1998 chevy with a fully rebuilt trans but it won’t move in drive but it does in reverse any ideas?
My first guess would be valve body related - improper shift linkage, solenoid fault, or something similar.
Love the details
My ECU overheating. What could be the problem?
Absolutely awesome video. Thank you sir!
happy new year pete!! thank you for all your wisdom and knoledge
Could a bad ecm throw battery charging system?
My check engine light came on plugged my scanner into the port and showed blank screen figure well my scanner is at fault plugged in a another scanner that scanner said can't communicate!!!🤔?
GMC sierra 2500 HD 2004 also the high beam indicator light stay on all the time!!!
You’ll need to understand bus networks to solve this one. But start by making sure you have power on pin 16 of the Diagnostic Link Connector
Thanks Pete, great video. I see your using the Autel lab scope lately, how do you like it compared to the Pico? I'm looking to upgrade my scan tool, and though I'm a Pico user, I really like the Bluetooth aspect of the autel/scope combination.
The Autel scope module works great and has many of the same features as the Pico.
Wow that's, amazing contact compound
Would a bad pcm cause my obd2 scanner not to communicate
O I trace an electrical issue on my 2010 mazda 3. 2.0l. Dtc code was p0768
Interesting about the Autel scope. What's the cost, how many channels, what's the warranty? Does it come with attenuators, that current tool and connection wires?
Using a scan tool to control a device is good, but can you control a device AND monitor it or the result on the same page with the appropriate pids? I used to do that with the I.D.S. we had at work.
Mike - the Autel is a 4-channel scope with possibilities I haven't even gotten to yet - like viewing the scope and scan data at the same time. You'll have to ask Autel for more info, though. Try logging on at www.Autel.com
Hi! Cannot find part # ECC11977U after market Engine Control Module for Chrslyer 2003 Town&Country 3.3LV6 motor car only has 102,000 miles would not do areas out for inspection so brought to a electrical specialist said it needs new ECM, but they don't make so try to get after market and one that is not programmed and he will put in and program just cannot get that part probably will have to junk car by next time for registration FEBRUARY 2024 car drives and works perfect! Would you try ECM that's already Programmed? Or are we taking a chance?
where can we get the stablent22 ?
I was told my 2007 CLS550 ECU processor is shot I don’t know what to do from here.
Can anyone tell me where the serial number is for the ecm for my 04 Dodge Durango?
I know this is a long shot , but I have to ask ! 06 Dodge Dakota SLT 3.7 had to replace what they called a multi function control module , it plugs into the fuse box under the hood , wiring harness plugs into it , ok , every light on dashboard is lit up , no wipers turn signals horn radio not sure what else ! It does start ! Hooked scanner up and it says error , no codes ! Was told the pcm is bad and not sending info to scanner , is the pcm and ecm the same thing ? And would it control all of my problems ? Help me
I had an 05 Dodge 65.9 diesel,,, no lights, no cruise, only headlights*, many no functions ,,,,, first got a new fusebox,,,,, then months later I needed that module plugged in on the side u mentioned,,,,, dealer tried 5 modules no good,,,,, rhen rhey got me A module and a new fuse box paired together and that worked**
I just discovered this channel and subscribed. Looking forward to more videos like this one.
Welcome!
What about an ecm that has been used as a jackstand on my tractor.??? I'll run some tests on it before I buy a new one.nect time I'm just going to use a big log for jackstand instead!!!
Awesome
Does map sensor cause malfunctions that lead to intermittent starting
Not likely. However, the 5v reference that it uses is shared with other sensors. That could be an issue.
why is my Electronic Throttle Body, buzzing .. key on?
Hi love your videos very informative!
Just a quick question I have an 86 ford OBD1 EEC- IV system which doesn’t communicate with any scanners so I can’t see any of the perimeters, do you know if there’s a module that can be connected to between the ECM and the scanner that maybe be able to read some or all of the perimeters?
I doubt it but had to ask 😀
What I do is back probe the sensor I’m checking at the ECM using my AES Wave uscope….
Tnx
Leor
This might be worth the investment. It does OBD II and OBD I, allowing access to data stream and vehicle self tests as well as reading codes (instead of counting flashes). www.tooldiscounter.com/product/actron-elite-obd-i-and-ii-autoscanner-kit-actcp9690
@@MotorAgeMagazine hi Tnx for your quick reply but I already have a snapon mt2500 scanner AKA the brick but can’t use it to read perimeters like fuel trims and other perimeters…. Too bad
@@Phantomas2011 how are things going these days?
Have you done a video on the ignition coils?
I've done videos on COP ignition systems, if that's what you're looking for. If not, what would you like to see?
I think my car needs a new ecm. But im not sure.
My fault code is p0001 ang o2 sensor my car won't start at all.do I probably need a new ecm?
Perhaps - but start with fundamental troubleshooting. Does it turn over normally, indicating some compression in the engine? Does it have a good strong spark? Is it getting fuel?
Car was stuck at work .I got a new battery it wouldn't start.i jumped with a jump box it started up with gas in it.when I turned the car off it won't start at all.obd scanner say fuel volume regulator circuit open.light and radio is on car won't even try to start
@@stephanmoney7493 What is the year, make, model and engine size in your car?
@@MotorAgeMagazine it's 2005 mazda6 3.0 6cyl automatic
@@stephanmoney7493 The code is an electrical issue that could be in the ECM or the Fuel Control Valve itself. It could also be something as simple as an unplugged connector or broken wire. You'll need a scan tool that can read the data, a wiring diagram, and a voltmeter/ohmmeter to diagnose and correct the problem.
Very UseFull INFO
Dont get me wrong what you have here is knowledge but I dont have the tools you have nor the skills, but my ECM is three plugs and one bolt so if I can but a used one for $100 bucks or so...if I simply take old out put in new and it solved problem ya. If not I am out 100 bucks but I would have to pay for diagnoses and tow truck .... buying ecm if cheap would be pretty quick would it not?
On late model vehicles, you can't simply install a used one. The VINs have to be matched and often the new module has to be programmed to the application.
@@MotorAgeMagazine thank you for your response
Happy God Blessed New Year Pete to you and your family.
Is there a link to the flow chart? Is it on YT or on a website, is it a series or one item?
I'd like to know how I can fool the ECU on my Honda Accord from a knock sensor readout? It's a cheap part that keeps tripping the light and a code and I keep clearing the DTC. The original one went toast and so I just purchased a cheap one to get me by for now. I hate the idea of spending over $200 bucks for a OEM sensor... any ideas?... besides an expensive part purchase? Btw, the prices on these knock sensors are all over the board, hard to know which one to get besides a OEM.
I'm not sure if plugging in a resistor matching the sensor's resistance will work or not - it depends on how the ECM tests the circuit and whether or not there is any kind of rationality test associated with it. As for parts, see if Duralast offers one for your Honda.
@@MotorAgeMagazine thanks, not sure what to do? It's looking like I'll have to go OEM. From my research, Honda vehicles are very particular on this part, aftermarket parts don't appear to work right. You can test these on a automotive scope for a specific sine wave, but I have no idea what's acceptable or what isn't, what the ECU rejects or not. It's like a top secret recipe... damn Hondas.
@@garyr7027 What is the code you are trying to address? Perhaps it isn't the sensor, but a circuit issue. And you can find "known good" waveforms on a variety of sites, like www.picoauto.com.
@@MotorAgeMagazine P0325 is the code, but I didn't get that code at first. My car started running really bad, no CEL and my code reader couldn't pull a code. It wasn't until I bought a scan tool that I got a code. Once I got that code, I got under the car to pull the connector off the knock sensor, and the sensor fell apart, then I got the CEL. So I replaced the sensor with a cheaper brand and it's been a issue since. Now every 400 to 500 miles or so the CEL will trip, the car runs rough, until I clear the code with my scan tool, and it'll run fine again until the CEL comes back on. The original sensor never did trip the CEL until I pulled the connector and I don't see anything wrong with the wire going too it, and that's the part that doesn't make sense to me.
@@garyr7027 Your comment that the car was "running really bad" has me intrigued. The knock sensor will not cause any drivability issues but is used to report to the ECM when any instance of detonation or preignition occurs. Is this code reoccurring and is there any other code stored or pending? (Check Mode $07 and Mode $03 on your generic scan tool).
Drinking out of a firehose... of great information. Thanks.
Great stuff.
Why do old fixed and cleared codes come back randomly after the mechanic has cleared them?
I have the same problem
How does one go from technician to working for motor age. That’d be a good job
I was just in the right place at the right time. I’m blessed to be able to do what I do.