Ford O2 Sensor Testing - wiring tests (no bias voltage)
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- Опубліковано 5 сер 2024
- During this case study, I use this Ford as an opportunity to cover my O2 sensor circuit integrity test in great depth. I not only explain its value during diagnostics, but also try to address any concerns or questions you may have as far as any potential to harm a computer. We also get to see the interesting backup strategy employed by Ford for O2 sensor issues, and how this can potentially mislead you if you’re not aware of it.
Engine Performance Diagnostics chapter 5
Symptoms
- check engine light (P1000, P1131)
Fix
- replaced the bank 1 sensor 1 O2 sensor
Tests shown
- using scan data (O2 signal and fuel trims) to evaluate O2 sensor performance
- how to recognize closed loop operation using only short term fuel trims
- understanding how a trouble code can change closed loop operation on some vehicles
- how to configure data lists on a Snap-On Solus Pro
- understanding Ford Keep Alive Memory (KAM) and why it’s important
- how to use propane to check for a lean condition or a sensor problem
- how to check for a bias voltage on an O2 signal circuit
- using sensor-side O2 wire colors to identify signal and heater circuits without a diagram
- how to perform an O2 signal circuit integrity test
- understanding why having the sensor plugged in or unplugged is important
- understanding current and voltage levels during the O2 signal circuit integrity test
Tools used
- scan tool
- propane
- incandescent test light
- digital multimeter
Playlist
- (Chapters 4 and 5) Fuel Trim and Oxygen Sensor Testing
• (Chapters 4 and 5) Fue...
Related videos
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- How to identify a bad oxygen sensor (signal fixed rich)
• How to identify a bad ...
- What is Oxygen Sensor Bias Voltage? (an SD Premium video)
• What is Oxygen Sensor ...
- How to quickly test an oxygen sensor circuit (GM bias voltage)
• How to quickly test an...
- O2 sensor testing (fixed lean) P0174, P0154, P0155 - Mitsubishi
• O2 sensor testing (fix...
For more information on this topic, I have written a “field manual” called Engine Performance Diagnostics which is available at www.scannerdanner.com as an eBook or paper book.
Want even more diagnostic training? Whether you are a DIY trying to fix your own car, someone looking to become an auto technician, or a current auto technician that wants to get more into diagnostics, subscribe to ScannerDanner Premium www.scannerdanner.com/join-sc... There is a 14 day free trial.
On ScannerDanner Premium I will bring you right into my classroom at Rosedale Technical College. You will find page for page lectures taken right from my book as well as exclusive classroom type case studies. What is so special about these classroom case studies? I pull live problem vehicles directly into my classroom and we troubleshoot them in real time, using and applying the theory and testing procedures we learn during the classroom lectures. There is no better on-line training of how to troubleshoot automotive electrical and electronics systems anywhere!
Disclaimer:
Due to factors beyond the control of ScannerDanner LLC, it cannot guarantee against unauthorized modifications of this information, or improper use of this information. ScannerDanner LLC assumes no liability for property damage or injury incurred as a result of any of the information contained in this video. ScannerDanner LLC recommends safe practices when working with power tools, automotive lifts, lifting tools, jack stands, electrical equipment, blunt instruments, chemicals, lubricants, or any other tools or equipment seen or implied in this video. Due to factors beyond the control of ScannerDanner LLC, no information contained in this video shall create any express or implied warranty or guarantee of any particular result. Any injury, damage or loss that may result from improper use of these tools, equipment, or the information contained in this video is the sole responsibility of the user and not ScannerDanner LLC. - Авто та транспорт
Worked at a half of dozen shops over the years, a lot of people hate on UA-cam. Every good diag tech I bump into, knows about you and are fans of your content. Thanks for all your help Paul.
This really means a lot to me. Thank you so much for the comment
Whenever I have issues with cars, I always type the problem into the search bar and add scannerdanner. Not interested in the other peoples videos. This guy explains his shit fluidly and leaves me excited to rush out to my vehicle and try the stuff. Awesome dude. 11/10. Ha ha.
Mr Danner. I know that this is an ancient video, but I am an engineer and I just found it and wanted to add something to your explanation. Your body's resistance is a few mega ohms, as is the cold sensor signal/ground pair and even the digital multimeter input circuit and the computer sensor input circuit (most people call it bias, but in electronics they call it open collector or high impedance). taking those mega ohm values into consideration where nothing is ideal makes the circuit voltage and current calculation a little different. There is a video for Eric (South main auto) and Ivan (pine hollow) where they have a truck with both sensors bad and Ivan shows that he carries in his tools a bunch of little resistors of different values. I think he did some trial and error and found that the best value was 22kohms or close. Thank you for all those years of great videos, I wish I can work for you as a helper for free one day as a form of payback. God bless
Man, I've worked at a few different shops w/ numerous lead techs and no one is on your level. No one has the confidence and testing skills to confidently determine sensor, wiring, or computer in such an accurate/simple way. Your videos and ebook is a god sent.
Started at a Ford dealership about 6 months ago, I'm the #2 Diag Tech. Been doing alot of factory training, so I haven't been watching your content for a while. Stumbled across this video, instantly remembered why I watched your content to begin with. Love it!
Thank you Michael!
Thank you so much for this comment! It is very nice of you to say this in a public setting. I owe you one
All I can say is you are great,,,,very good video,,, don't worry about your voice,,, you have a great voice you are not roaring,,, you got the right DB level of recordings,,,keep it up and thank you for all the helpful videos.
I was directed here from a forum post at Taurus Car Club of America, and I'm blown away. This is perfectly done, with everything well explained and shown. What a wonderful resource. Thanks for your dedication and excellent work ScannerDanner.
There is nothing better than being able
The teacher has the theory to apply it in practice
We thank you
This is superb Paul,I particularly like the circuit integrity test using your body....Many Thanks 👍🏻
Super info. Especially since I’m working on a 2000 Taurus dead upstream O2. Got to this video thru Paul’s book. It links automatically to you tube. Sweet
Exactly the test I need for what I'm working on great time saver... Thanks Paul again!
It's like a episode of myth busters! I did some body signal integrity testing the other day. The guys in the workshop were amazed! Very educational video Paul.!
Paul, another outstanding troubleshooting video!!! Love your technique, much appreciated !!
All I'm going to say is your videos are so informative and I've learned so much from them. Your a awesome teacher. Thanks for all that you do.
Thanks for watching!
+ScannerDanner Premium So if i keep blowing a fuse can one on my sensor be faulty Please contact me back ASAP
Outstanding Paul, I like the way you illustrate irrelevant of the resistance in series with 12 v battery, you will still drop enough voltage into the O2 signal line to the CPU, to peg the CPU interperted signal voltage. You are a great teacher Paul by reinforcing your troubleshooting setups with backed up voltage signal readings.👍👍👍👍👍👍👍
Thank you so much. Awesome feedback
excellent quick and in depth tutorial to o2 troubleshooting.. thanks!
another great video, without resetting the KAM, i would of immediately thought there was a PCM problem,would of thought erasing the code would have been enough.Great job Paul,i've learned so much from your channel,keep up the good work and im waiting for the new lectures to come out.
Hey Paul, Let me give thanks for sharing the Knowledge on how to test the O2 sensors Using Bias Voltage and the PCM Response Testing. I'm assuring you that now I can take 3 Minutes to diagnosis Fault Codes about O2 sensors.
Always on your back Danner ❤❤❤
Another awesome video. My favorite part was how you proved the myth that directly applying 12v to the O2 signal wire did NOT fry the computer, though the circuit is only designed for 1v of current. Looking forward to viewing part 2 on the MAF!
Nice video Mr. Danner I like all your videos and im learning from you thank you apriciate what you do for us thank you again!!!
The BEST O2 video by far. Didn't leave any room for any doubt. Thank you for taking time sharing your experiences.
Very nice video, thanks for sharing!
Thanks Paul, Nice video.. I learn one or other things in your every video.. all the tips and tweaks that u give are priceless. Simply amazing... keep it up and keep doing
great video paul. if you made it 20 times on different vehicles I would still watch it . because it sometimes takes me that long to grasp things now.but its getting there.
cheers.
Paul I have learned a lot from your videos even know I am a DIY . I always say " A Nosy Tech Is A good Tech " They want to find the rot cause of a issue not throw parts at it !
Hi thanks for the videos just to let you know we had a flat lean burn .02 volt 02 changed sensor computer tested signal circuit get worked great. Propane test still flat lean. A real stumper. The fix was to reinstall the plug wires that the previous shop installed incorrectly. Moral to the story is they measure oxygen not fuel. When the plugs finally lit the mixture oxygen was used up.
You are a great teacher
I thank you Paul because you have taught me not to be a parts changer and to think outside the box, I have your book and its a tool much like my ratchet.
So you can use your body for electrical circuit integrity testing. That's awesome!
Great lesson
very nice diagnosing
you are welcome and thanks for the comment
Paul you had me at Hello.Just saying that you have been sending a rich signal with your test light or body to the O2 for 20 years is enough for me to be convinced that it is very safe . Thanks.And who the heck watched this awesome video and gave a thumb down?
thanks for this , learning alot
thanks for the new tips. Im learning more
for sure! Thank you!
Great video brother.
Good work Dan
thanks for the tip Michael! makes sense, although I would think that the trim numbers would have had more of a swing due to the delayed reaction from the converter doing its job. So higher positives and deeper negatives and we weren't seeing that. it almost mirrored the other bank.
Thank you Cesar!!
Great video mister Paul. I always believe that giving 12V on O2 circuit trough our body we give 1V because of our resistance. Never thought to check that... :))) . Thanks for sharing this.
AWESOME VIDEO!!!!!
HEY PAUL I GOT YOUR EBOOK I HAVE SEEN. GOOD VIDEOS IN OTHERS CHANNELS BUT YOURS. THE BEST. YOU ARRRRRRRRE THE MAN THANKS FOR SHARING
great video!
Great video
Great work .....thanks
I agree and I believe the programming is set to not use the signal again until it crosses the 450mv threshold. I thought I did a good job showing the reaction maybe I needed to explain that part a little better
nice! that is exactly how I wanted it to be. a part of your "tool box"
very nice , thank you for your time
Damn, it just keeps getting better!! Yipeeeeeeeeeee.
Only need 23 more.......
Love the videos
Scanner Danner, I am having trouble with a 1996 chevy 1500 V8 vortec. The truck starts and idles fines and sounds great but... when you rev the motor it acts like it wants to die at 2000 RPM. Also when you put it in gear the ABS light comes on and the truck stumbles on its face like its hit limiter at 2k RPM, any thoughts?
Let’s face it the guy is good !!! . Thank you for this vid sir .
Good Evening ScannerDanner take care and have a great day ScannerDanner 👍 God bless you ScannerDanner 👍
Great tutorial thank you 👍
From Nick Ayivor from London England UK 🇬🇧
Good O2 study,., Thanks,., gracias.,
I would like to hear your theory of how the O2 signal circuit is checked before start-up on this design. Ford does not use a bias voltage on either the signal or ground wire.
The heater circuit can be monitored immediately, but I don't think the signal circuit can be on this design.
I believe it ignores this sensor immediately due to a previous fault and will not use it again until it sees activity on the signal. (voltage must cross the set point of 450mv)
gracias!!! muy buenos videos y si voy a comprar el libro.
thank you my friend!
Great lectures, please I have an issue I would like to ask some questions, there in a 2007 Nissan Pathfinder in my workshop, customer complain that the vehicle take a lot of fuel, fault codes are P0488 and P0463. I’ve checked the resistance of the oxygen sensors, all the value seem to be within range, but I noticed that the MAF sensor has no activity with value stuck at .1g/s, the LTFT has no activity while the downstream oxygen sensors are stuck on 0.288 volts while the upstream sensors has very little activity and the ECT is about 187degrees centigrade, at high RPM of about 2500rpm the STFT drops tp -20 on bank 2 and -14 on bank 1. No fault code related to the oxygen sensor. I’m thinking it a wiring problem. What’s your take.
correct, and I did say that in one part of the video. we did have some amount of voltage drop through my body so there was some amount of current flow taking place.
hi there , wondered if you can help a wee bit?
my bank 1 sensor 1 is throwing out up to 800 plus and back down to low numbers that's constant, not sure if numbers be so high?
my bank 1 sensor 2 numbers are matching the upstream 02 sensor numbers
she failed emissions! I've bought new sensors so need to fit them once get old ones off!
any thoughts would be something to look into b4 I go for new cat!
this is a Ford thing, of course with the right scan tool too.
On systems that do not offer this, a battery disconnect works too.
Code P013A Bank 1 sensor 2 O2 sensor. '12 Ford E350, 5.4L flex fuel engine.Replaced the sensor still get the same code after driving about 140 miles straight or 1 stop and driving another 15 miles the next day. Wiring issue, PCM issue? Also when the ck eng light for this codem fuel gauge reads normal. Ck eng light not on, fuel gauge reads about 1/8 of a tank lower than what it should be. Any ideas?
I wonder how long it takes the computer to recognize the new O2 sensor and correct fuel trim. Or is it better to go ahead and reset KAM?
thanks Frank, almost done with MAF sensors, it is a longer one. Then I am doing Section 20 after that (idle speed controls)
thank you so much. what a great compliment. great way to start my day.
All good stuff.
Hi
I have bmw 328i 2008
The o2 sensor before the catalic is 2.04v
When i unplug the sensor it’s stay at 2.04V
No change so what’s wrong
I have the same problem with my 99 crown vic codes 1131 and 1152 I changed all 4 o2s and I have the same problem car runs lean so the pcm is trying to correct it but running rich how do I fix this problem and how can I erase the kam without using a solus pro??
Would this also work for checking wire integrity on other sensors (using your body as the resistor) ? Since you are only sending aproxx 7v down the signal wire to the pcm would you be able to check say the signal wire integrity from a TPS signal wire, feeling confident you will not damage PCM.
Hey paul ive bin wanting to ask you how do you feel about checking circuit integrity with the load pro
Also, the way Ford did their code in these earlier ECM's, they check for dead sensors before startup. So it would ignore the bad sensor immediately and store that and LTFT data in its keep alive memory.
super Paul - thanks
I replaced both updown and the one downstream O2 sensors on my Ford E250 ('98) with Motocraft sensors. Also changed plugs, air filter and that sensor that mounts to the EGR valve. I've also replaced the MAF sensor, sealed all vacuum leaks, no Sevice engine light and I can still smell strong raw hydrocarbon fumes in the exhaust. Can you point me in right direction here? Would a burned out Cat. result in these hydrocarbon fumes? My scanner shows normal readings, I think the max voltage is ~ .790 mV upstream and about the same downstream. I'm going to take a look at the fuel trims later after watching your video - Thanks, Reese
Hey paul what do you think of the hook from power probe? it has the ability to supply a ref voltage that you can control
I have an 04 f250 that's throwing two lean codes and a rich code for bank 1, codes p2195stuck rich,p2196 stuck lean, and p0171 lean bank1 I didn't see any vacuum leaks and the o2 seems to be working properly also only one cat converter so I don't think it's clogged. Any ideas on where I should head with testing?
great video about o2s,, but you did not put direct line positive in pcm o2s signal.. i have seen shorted burn signal positive/nega signal.. heater ground and positive heater,, but im currious about giving a direct 12v to the o2signal and afraid that it will fry the ecm..??
Sorry one question why the downstream sensor is not chaging its on "0"
Can you apply some voltage by external power supply?
1 test is missing in opinon. Would this Ford ECU clear the keep alive memory by itself and using the new O2, if you simply would have changed to a new sensor? Is clrearing the fault codes enough in this case or has he ECU to relearn. On some crazy Toyotas you need to clear the codes, unplug the MAF sensor, clearing the codes again and restart the engine to even accept a new O2 (wideband) sensor.
perfect fix
Paul if the keep alive memory had not been cleared, would the learned LTFT on bank 1 have taken very long to come down to normal after the repair?
It is becoming more and more difficult to answer questions here. I have 80,000 people asking me for help now. So I have created a forum to help you guys better. It is free to join and we can exchange pictures, wiring diagrams and waveforms if needed to help guide you through the process of troubleshooting your vehicle. Thank you so much! Hope to see you there.
Paul Danner (ScannerDanner)
www.scannerdanner.com/forum/post-your-repair-questions-here.html
Awesome❤
Hi Paul, how do I interpret livestream data on a fault code reader? Is there any info available from the manufacturers? I have a VW Passat and Polo.
BAFX adapter, and Torque app
Can you use a AA battery (1.5 volts) to test the integrity of the signal wire on the Oxygen Sensor?
Yes but the battery must be grounded to the car
G.N, if u did put d +lead of d merer on d + on d batt what would happen with that test.
This si gold!
Dan please what does it mean when shrtft 12 is stuck on 99.21°/ is this normal?
STFT12 is a downstream fuel trim % and is not used on most cars. In other words it is useless data
What about testing the signal and earth circuit with just a DMM or test lamp? Could you use your body as a resistor between the red probe of DMM and above wires?
you can do that and even use your ohm and diode scales as a source to do a signal circuit integrity test. I have a great series on this on my premium channel if you are interested www.scannerdanner.com/scannerdanner-premium-chapters/chapter-10-signal-circuit-integrity-testing.html
There is a 14 day free trial and it is only $11 a month after. Hope to see you there!
My guess would be that there is a zener diode across the input to the ECM clamping the voltage at 1.6 volts, and also probably a resister in series which is evident by the fact that the voltage at the t-pin was over 6 volts when touched. The purpose of the zener of course is to protect the input against over voltage input. Depending on the zener being used I would guess the maximum current would be somewhere between 0.5 and 1 amps. There's no way your body would ever provide enough conductance to get the current anywhere near those levels, so you're not in danger of damaging the input circuit in the ECM.
Hi Paul ive just discovered that some of the thimble type zirconia o2 sensors do not have a PWM heater but rather a constant 12v. Thought a 2004 hyundai had a faulty driver but some research showed it is constant 12v ... but pulses at very beginning of warmnup cycle. Not seen much info on these and dont think u mention them? Have u had experience with them?
yes of course! I have a ton of video talking about PWM heater circuits. This one in particular was really good,
ua-cam.com/video/-lUYRqaYvYI/v-deo.html
ua-cam.com/video/gtTKOuu6EPw/v-deo.html
Oh crap!! I have been mis identifying the location of o2 sensors. I thought that O2S11, was upstream sensor bank 1, and O2S21 was downstream sensor bank 1. I am glad I rewatched this video cause I am trying to diagnose a taurus O2 problem, and that would have had me all F&*ked up :)
can you reset the KAM with most scan tools? at least a bidirectional one. genesys etc
So is it safe to add propane to the air box of a mass air flow sensor engine, but it's not safe to add any sort of liquid fuel source, correct?
It's risky with liquids as you could potentially damage the MAF but my brother does it all the time lol
I have been drug around the bushes on one. 1996 Bronco. 5.8l EECV OBDII all the good stuff. Codes are for heater circuit faults. Test voltage at sensor I get battery voltage on both pins for the heater on all sensors. Live data shows they're cold at start up but after running it for a while the o2's report normally. Any ideas?
Do both heater wires stay at 12 volts with it running? One should drop to ground. If it's staying at 12, you are missing a ground. This can go directly to the block on these older systems but I think yours are computer controlled.
ScannerDanner, thanks for the suggestion. I haven't tried backprobing while running. Just tested while in run engine off. You are correct though, four wire sensor. Computer controlled ground.
my car has only 1 bank and 1 O2 Sencer which is give me 830 to 890 mv reading
O2b1s1= 830-890mv
STFT B1S1= -25%
LTFT B1S1= 95%
PLEASE give me possible causes and suggestions.
yep. one final check is the signal wire integrity. unplug the sensor and it should read near 5v on the signal wire. watch my latest video on testing the dpfe sensor for more help. it was on a taurus i think
Hi Mr Paul I'm Salah from Oman 🇴🇲
I had the same issue with my 2009 gmc terrain V6 engine .
I had O2 sensor code,I looke at the live data and I noticed 1)open loop bank 2
2) 0% STFT on bank 2
Two evidences for a bad O2.
I've replaced it and it's working now.
freakin awesome!!
I did not know that. If it has the ability to do that then I guess it is time to get one!