Hi Carbon, just got back from mechanic with my daughters 2010 Cobalt. She had the exact same problems with crazy instrument panel that you had. I too checked and tried a number of remedies from Google with no luck. Long story short, the mechanic tracked the problem back to the radio/stereo ( stock), said it was bunging up electrics with bad signals (?). He pulled the fuse on the radio and crazy dash lights and stuff went away. Put fuse back in which reset radio, everything worked fine for a bit, then fubared again. Pulled radio fuse and everything was fine with crazy dash. Sooooooo…….crazy dash gone at moment, no music though (don’t know which kid thinks is worse though). Found your vid while looking for stereo replacement in Cobalt. You have a great presentation style!!!!! New subscriber!
Wow, that’s so crazy that the radio caused that. Yet, from all the stories I’ve read/found about the electrical on these cars, I guess I’m not surprised. Hopefully you get that new radio going and dash craziness never returns. Thanks for the kind words on the video, too, definitely appreciated, especially with the chancel being so new. And thanks for watching abs subscribing!
Thanks for watching and the feedback, Mando. Yeesh - At least with the Cobalt the PCM and TCM are easy to find and swap out; might be one of the very few things that are easy with this car... :)
This is the same problem I'm dealing with now. After doing the steps you already mentioned short of the ECM replacement, and based follow up comments, I'll probably start my investigation with the BCM. I'll follow up with how that goes.
Also if you replace the BCM you may need to do the key relearn procedure. (Charge your battery first) Then put key in ignition (the new/used bcm may give you a key lock light) You will then wait for the light to go out, after 10mins of the car on the light will go out. Do this cycle 3times and your car will start right up with a used bcm
Thanks for watching, Steve! Totally agree; such a sad moment when I got the text “Dad, it’s doing it again…” Only thing left is to try replacing the TCM. After that it’s down to the worst option - random wiring.
The problem is the TCM fuse has a GMLan data signal running through it which produces square waves and pits the fuse. Repeatedly. DC fuses generally deal with sine waves I believe. Not sure how you could go about making a better fuse. Littelfuse 10a hold up a little better than some of the other ones I've tried. I hear using dielectric grease on the BCM connectors helps.
I had this same issue and replaced the TCM and ECM just to have the issue still happen here it was the speed sensor and the wiring was compromised. So always check the simple stuff first.
Makes me wonder if either of my TCM/ECM work for this car, also if my BCM is even good. Been having Reduced Engine Power on and off for a year now and still cant pinpoint it on my Pontiac G5 07. Someone even thought it was ICM related, but I dont believe this vehicle has a ICM that I can see.
Wife drives an 09 Cobalt. For a couple months its started sounding like a lawnmower. Before that, if would randomly have freakouts where the power steering would go away and the moh and rpms would bounce randomly. Also the radio doesnt light up or work. Could be connected issues not sure.
i have exact same issue on 05’ cobalt ls sedan everything went haywire after parked with engine running then when i was ready to go it stated to misbehane dash,power steering engine and transmission went wonky when i got home and turned it off for a while and turned on everything went fine so i test drove seems fine …..i couldnt figure that out i ran obd ii readr says 3 codes as u2100 and u0100 and tpm switch stuck on …….
make sure the bottom ecm plug has no oil residue in the ecm plug area. if it does oil pressure sensor is wicking oil through the wiring and that oil causes all kinds of issues. (if oil is there) clean it out real good with contact cleaner. put some dialectric if you wan on the socket and replace your oil pressure sensor. (sounds crazy i know but its a thing)
I'm having similar issues on an 2009 Cobalt. I added a ground wire but that didn't help. I will continue my research and efforts. Random problems are the worst to figure out.
I have been expriencing the exact same issue with my 2010 cobalt. I have been to every mechanic in my area about, and after over $1000 in fees, still no fix. After watching this, I think I'm going to give this method a go and see if I can fix it myself. THANK YOU!! Has the issue happened again?
Thanks for watching, Darrell! I hope this resolves it for you. Unfortunately, it came back for me. Check out the pinned comment at the top and some of the other comments I’ve replied to for the details.
Funny my 2010 is completely out now not intermittent, i was around 130-135k as well, and when my wife had the car they repaired a wire bundle near the fuel tank from what she said. Also showing the car lock icon and I've lost all my gauges. I'm looking at replacing the instrument cluster. I've seen a few videos with intermittent issues, but none where it shuts off. Also if I turn ignition to accessory the engine stays running. Just got it back from a mechanic like this.
Oh wow. That sucks! I was always afraid this would happen to mine, but it never did. One time I did have it refused to work/start for 5-10 minutes but after letting it sit long enough, it came back as if it never happened. So bizarre! Sorry I don't have any good advice for you on this one. I hope you're able to find and kill the gremlin!
Get a used body control module (BCM) preferably from a 2010 cause yours is a 2010. Also same type of car sedan/coupe. If yours has power windows get one with power windows. Record the mileage before you unplug it. Then swap it out. Order a OBDstar x300m and program the new mileage to it. That should fix your issue!! You can have a shop program your cars vin# to the BCM and also the possibly the radio, depending on which one you have
Thanks for watching, Carson! Well, if replacing the ECM and TCM (ua-cam.com/video/Lh-K7NWa6yI/v-deo.html) doesn't do the trick, BCM will probably be next.
Found that the issue on our 07 hhr was actually the wiring going into the ecu itself the oil pressure sending unit was leaking oil and it had seeped up the line to the computer when you pulled bottom connector off of computer it had a sizeable amount of oil in the connector cleaned with electronics cleaner and replaced oil sensor and issues went away
I'm glad you mentioned this - I'd seen this in a couple of posts but when I pulled my connector apart, I didn't have oil anywhere and I never made mention of it in my video. Thanks for the reminder and tip for folks. And thanks for watching.
I wanted to ask from which website you ordered this part and how much does it cost. I am facing same issues with my Pontiac G5 as cobalt and Pontiac G5 uses same parts. And in which country you ordered this part
There could be any number of reasons that it's in safety mode (I'm not really sure on them - just speaking from experience with my Jeep Wrangler). One could certainly be the computer/ECM but it might be something else (sorry, I know that doesn't help). The ECMs do need to be VIN matched, so it won't be functional (or at least not 100% functional) if you just take one off another Cobalt and install it. The ebay link in the video description is where I got my VIN-programmed ECM replacement (and there are other places out there that does it as well, I'm sure). Thanks for watching, Benny, and good luck.
You shouldn't need them; they should be grounded through the harness, but some people had success by adding the additional ground wires. It didn't make a difference in my case.
bad connection take all fuses out and relays reinstall clean all connections to ecm and bcm and trans. Problem fixed hasn't came back even drove it to other states. Before i as afraid to drive to the store. Wasted money replacing just about everything and still had say issues Do that before spending any money. Only issue i have know is the cruise works when it wants too
Wait I found the freaking solution lol drum roll please. So my craip 05 Chevy colbalt was jerking when shifting gears the speedometer goes all wonky and the power steering goes out. And there for awhile I would drive it and it would do it every few days to everyday. So I found a video on UA-cam where they grounded a wire from the tcm to a metal part on the car. My stepdad is a mechanic and said u cannot ground wire to the tcm it has to be a bolt or something. Well sure the f enough he figured it out and a ten minutes ground a plain ol AutoZone wire from the tcm would work but it did all issues resolved!!!! If u this sounds like your problem I can find the video and share below. He also cleared all codes. Oh my I finished your video well craip idk then. He did tell me that he had to move the grounding a few times though to get it to work. I need to give him a gold star
@@DanielSanchez-kh5td ua-cam.com/video/i3K5AFR7vM8/v-deo.html Now don't mind the vehicle it still works for colbalt. There's another video with the same fix but it's a colbalt however doesn't really show how he fixed it. My car is running fine still
@@DanielSanchez-kh5td ua-cam.com/video/EzQZbGp14ro/v-deo.html. Also my stepdad said u cannot ground to tcm it has to be a bolt or something. I don't know anything about soldering so I guess it makes a difference on types of metals. Also it took a few tries he would have to move it a few times. like tinkering with it. Good luck
More details in the description but this didn’t end up fixing it for me, nor replacing the TCM. The car then got totaled in a collision (video about that in the channel) so I’ll never know whether I’ll have been able to fix this issue.
I don’t have experience with this seller but take a look at this listing. If that’s not what you need, try contacting them and asking. Also just search eBay for “Chevy Cobalt ECM”. Good luck and thanks for watching! www.ebay.com/itm/256205882610?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=Wj-iH4tZT6W&sssrc=4429486&ssuid=_D1cUevjTm-&var=&widget_ver=artemis&media=COPY
@@stevenwhitley6286 Thanks for watching and I hope you or someone can figure this gremlin out. It really sucks for a lot of people for it to not have a fix yet.
A commenter, spikedspike, may have discovered the cause of this issue. I made the linked video hoping to make the possible resolution available to more people: ua-cam.com/video/oGAfw2xpucU/v-deo.html
This is great! I wish I still had the Cobalt. I would definitely go check this out. I don’t recall any oil in the ECM connector when I replaced it but based on the comments by spikedspike you could still have this issue even if you don’t see oil. I hope this resolves the issue for people. It would be great if we start getting comments on your video (well done, btw) or here on whether this fixes it or not.
Yes, the problem came back after about 6 weeks. I then moved on and replaced the TCM (ua-cam.com/video/Lh-K7NWa6yI/v-deo.html). It's currently been about 12 weeks since I replaced the TCM and the issue hasn't come back. However it's going to have to be at least 6 months of no issues before I fully declare it fixed. Thanks for watching!
Just to add another follow-up. After 130 days, the issue came back again. So, after replacing the ECM and TCM, the randomly occurring problem still occurs. So frustrating!
@@CarbonsDIYGarage I have a 2005 cobalt, has been a nightmare lately. I grounded my TCM, with 2 ground wires to shock tower, and still the transmission bucks terribly. However, whenever I add a little 10 W 30 to the 5 W 30, it seems to work ok for a week or so... then the bucking problem returns. I will never buy Chevy, or any American brand, ever again.
@@tomlindroos828 Thanks for watching, Tom! I can't agree more on your assessment. I got this Cobalt for a really good price and boy - I really have to keep that in mind when I deal with this stuff. It's really disheartening how the US brands (well, the GM and Chevy brands in my personal experience) have slipped so much over the past couple of decades. I hope somehow your Cobalt starts behaving better for you. Good luck!
@@CarbonsDIYGarage The sad thing about the Cobalt is that the mechanicals are great, but the lousy electric modules ruin would could have been a classic Chevy..... so sad. From now on I'm buying Japanese.....
Check out the video description for extra info, parts, tools, torques, and any updates.
Hi Carbon, just got back from mechanic with my daughters 2010 Cobalt. She had the exact same problems with crazy instrument panel that you had. I too checked and tried a number of remedies from Google with no luck. Long story short, the mechanic tracked the problem back to the radio/stereo ( stock), said it was bunging up electrics with bad signals (?). He pulled the fuse on the radio and crazy dash lights and stuff went away. Put fuse back in which reset radio, everything worked fine for a bit, then fubared again. Pulled radio fuse and everything was fine with crazy dash. Sooooooo…….crazy dash gone at moment, no music though (don’t know which kid thinks is worse though). Found your vid while looking for stereo replacement in Cobalt. You have a great presentation style!!!!! New subscriber!
Wow, that’s so crazy that the radio caused that. Yet, from all the stories I’ve read/found about the electrical on these cars, I guess I’m not surprised. Hopefully you get that new radio going and dash craziness never returns. Thanks for the kind words on the video, too, definitely appreciated, especially with the chancel being so new. And thanks for watching abs subscribing!
There's a ground under the steering the steering wheel near the radio mine was lose and tightened it up and never done it again
Great tutorial,Thanks! needed to figure out how to pull the ECM on my 09 HHR.Took me 6 months to figure that out. 🤣
Thanks for watching and the feedback, Mando. Yeesh - At least with the Cobalt the PCM and TCM are easy to find and swap out; might be one of the very few things that are easy with this car... :)
This is the same problem I'm dealing with now. After doing the steps you already mentioned short of the ECM replacement, and based follow up comments, I'll probably start my investigation with the BCM. I'll follow up with how that goes.
Good luck with your quest to figure it out! Looking forward to your updates. Thanks for watching, Vincent.
Also if you replace the BCM you may need to do the key relearn procedure. (Charge your battery first) Then put key in ignition (the new/used bcm may give you a key lock light) You will then wait for the light to go out, after 10mins of the car on the light will go out. Do this cycle 3times and your car will start right up with a used bcm
Great Job Ed! I hate that the problem showed back up. Electronics can be a real PAIN!
Thanks for watching, Steve! Totally agree; such a sad moment when I got the text “Dad, it’s doing it again…”
Only thing left is to try replacing the TCM. After that it’s down to the worst option - random wiring.
Hi
Please can I get your number
Thanks very informative. I'll let you know when it will be changed
The problem is the TCM fuse has a GMLan data signal running through it which produces square waves and pits the fuse. Repeatedly. DC fuses generally deal with sine waves I believe. Not sure how you could go about making a better fuse. Littelfuse 10a hold up a little better than some of the other ones I've tried. I hear using dielectric grease on the BCM connectors helps.
Also check the fuses on the BCM when you get a replacement
Thanks bro 🙏🏼
I had this same issue and replaced the TCM and ECM just to have the issue still happen here it was the speed sensor and the wiring was compromised. So always check the simple stuff first.
Makes me wonder if either of my TCM/ECM work for this car, also if my BCM is even good. Been having Reduced Engine Power on and off for a year now and still cant pinpoint it on my Pontiac G5 07. Someone even thought it was ICM related, but I dont believe this vehicle has a ICM that I can see.
Very good education
Wife drives an 09 Cobalt. For a couple months its started sounding like a lawnmower.
Before that, if would randomly have freakouts where the power steering would go away and the moh and rpms would bounce randomly. Also the radio doesnt light up or work. Could be connected issues not sure.
i have exact same issue on 05’ cobalt ls sedan everything went haywire after parked with engine running then when i was ready to go it stated to misbehane dash,power steering engine and transmission went wonky when i got home and turned it off for a while and turned on everything went fine so i test drove seems fine …..i couldnt figure that out i ran obd ii readr says 3 codes as u2100 and u0100 and tpm switch stuck on …….
My 2015 cruze ltz rs has that issue sometimes but then goes away.
I drive same Chevrolet cobalt 2009.
2.2L engine, 5 speed manual gearbox same issues with the electrical and engine fire ups and down
make sure the bottom ecm plug has no oil residue in the ecm plug area. if it does oil pressure sensor is wicking oil through the wiring and that oil causes all kinds of issues. (if oil is there) clean it out real good with contact cleaner. put some dialectric if you wan on the socket and replace your oil pressure sensor. (sounds crazy i know but its a thing)
My battery wont charge, i replace alternator ,cleaned all grounds , new battery , stil no charge
Is it the solenoid on the shifter ?
I’ve never seen them grounds on any cobalts Tcm to ecm
I'm having similar issues on an 2009 Cobalt. I added a ground wire but that didn't help. I will continue my research and efforts. Random problems are the worst to figure out.
The worst indeed! I hope someone eventually figures it out. Thanks for watching.
I have been expriencing the exact same issue with my 2010 cobalt. I have been to every mechanic in my area about, and after over $1000 in fees, still no fix. After watching this, I think I'm going to give this method a go and see if I can fix it myself. THANK YOU!! Has the issue happened again?
Thanks for watching, Darrell! I hope this resolves it for you. Unfortunately, it came back for me. Check out the pinned comment at the top and some of the other comments I’ve replied to for the details.
Funny my 2010 is completely out now not intermittent, i was around 130-135k as well, and when my wife had the car they repaired a wire bundle near the fuel tank from what she said. Also showing the car lock icon and I've lost all my gauges. I'm looking at replacing the instrument cluster. I've seen a few videos with intermittent issues, but none where it shuts off. Also if I turn ignition to accessory the engine stays running. Just got it back from a mechanic like this.
Oh wow. That sucks! I was always afraid this would happen to mine, but it never did. One time I did have it refused to work/start for 5-10 minutes but after letting it sit long enough, it came back as if it never happened. So bizarre! Sorry I don't have any good advice for you on this one. I hope you're able to find and kill the gremlin!
Get a used body control module (BCM) preferably from a 2010 cause yours is a 2010. Also same type of car sedan/coupe. If yours has power windows get one with power windows. Record the mileage before you unplug it. Then swap it out. Order a OBDstar x300m and program the new mileage to it. That should fix your issue!! You can have a shop program your cars vin# to the BCM and also the possibly the radio, depending on which one you have
Thanks for watching, Carson! Well, if replacing the ECM and TCM (ua-cam.com/video/Lh-K7NWa6yI/v-deo.html) doesn't do the trick, BCM will probably be next.
Waiting on a new ecm to be flashed. My dad's 10 keeps giving a knock sensor code and it got traced to a bad pcm ... hopefully ot works
Good luck! I hope that fixes it for you. Thanks for watching.
Found that the issue on our 07 hhr was actually the wiring going into the ecu itself the oil pressure sending unit was leaking oil and it had seeped up the line to the computer when you pulled bottom connector off of computer it had a sizeable amount of oil in the connector cleaned with electronics cleaner and replaced oil sensor and issues went away
I'm glad you mentioned this - I'd seen this in a couple of posts but when I pulled my connector apart, I didn't have oil anywhere and I never made mention of it in my video. Thanks for the reminder and tip for folks. And thanks for watching.
I wanted to ask from which website you ordered this part and how much does it cost. I am facing same issues with my Pontiac G5 as cobalt and Pontiac G5 uses same parts.
And in which country you ordered this part
The parts information is in the video description. I bought it off eBay. Good luck with your G5 and thanks for watching.
I have a 2010 cobalt with in safety mode if I change the ecm Would This solve my problem? And if a ecm from another cobalt would work bolt on?
There could be any number of reasons that it's in safety mode (I'm not really sure on them - just speaking from experience with my Jeep Wrangler). One could certainly be the computer/ECM but it might be something else (sorry, I know that doesn't help).
The ECMs do need to be VIN matched, so it won't be functional (or at least not 100% functional) if you just take one off another Cobalt and install it. The ebay link in the video description is where I got my VIN-programmed ECM replacement (and there are other places out there that does it as well, I'm sure).
Thanks for watching, Benny, and good luck.
I am having the same issue, with my 2010 HHR. Im about to replace the ECM. Hopefully that works.
Thanks for watching! Best of luck with yours - I hope this resolves it for you.
@@CarbonsDIYGarage thanks, it should be here in 2-7 days, so ill let you know!
@@CarbonsDIYGarage unfortunately it wasn’t the ECM for me. Back to the drawing board.
I noticed that I do not have ground wires connecting the ecm and tcm
You shouldn't need them; they should be grounded through the harness, but some people had success by adding the additional ground wires. It didn't make a difference in my case.
But please I will need your help
bad connection take all fuses out and relays reinstall clean all connections to ecm and bcm and trans. Problem fixed hasn't came back even drove it to other states. Before i as afraid to drive to the store. Wasted money replacing just about everything and still had say issues Do that before spending any money. Only issue i have know is the cruise works when it wants too
Wait I found the freaking solution lol drum roll please. So my craip 05 Chevy colbalt was jerking when shifting gears the speedometer goes all wonky and the power steering goes out. And there for awhile I would drive it and it would do it every few days to everyday. So I found a video on UA-cam where they grounded a wire from the tcm to a metal part on the car. My stepdad is a mechanic and said u cannot ground wire to the tcm it has to be a bolt or something. Well sure the f enough he figured it out and a ten minutes ground a plain ol AutoZone wire from the tcm would work but it did all issues resolved!!!! If u this sounds like your problem I can find the video and share below. He also cleared all codes. Oh my I finished your video well craip idk then. He did tell me that he had to move the grounding a few times though to get it to work. I need to give him a gold star
Can you share the video? thank you
@@DanielSanchez-kh5td ua-cam.com/video/i3K5AFR7vM8/v-deo.html
Now don't mind the vehicle it still works for colbalt. There's another video with the same fix but it's a colbalt however doesn't really show how he fixed it. My car is running fine still
@@DanielSanchez-kh5td ua-cam.com/video/EzQZbGp14ro/v-deo.html.
Also my stepdad said u cannot ground to tcm it has to be a bolt or something. I don't know anything about soldering so I guess it makes a difference on types of metals. Also it took a few tries he would have to move it a few times. like tinkering with it. Good luck
Have you found a fix yet? I’m also having the same exact problem!
More details in the description but this didn’t end up fixing it for me, nor replacing the TCM. The car then got totaled in a collision (video about that in the channel) so I’ll never know whether I’ll have been able to fix this issue.
Do you have a different link? The link is no good?
I don’t have experience with this seller but take a look at this listing. If that’s not what you need, try contacting them and asking. Also just search eBay for “Chevy Cobalt ECM”.
Good luck and thanks for watching!
www.ebay.com/itm/256205882610?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=Wj-iH4tZT6W&sssrc=4429486&ssuid=_D1cUevjTm-&var=&widget_ver=artemis&media=COPY
You didnt show plugging the coolant line back in
Dang it. I was hoping nobody would notice! I did reconnect it before closing the hood and starting it up.
Thanks for watching.
Did the check engine come back on?
More details in the video description but yeah, it came back after about 6 weeks. :(
Thanks for watching, Aaron.
A year later did it fix it for good? I have this exact problem
Yeah. You can read the saga in the video description. After it happened in October, it didn’t happen again before the car got totaled in December.
@@CarbonsDIYGarage
I posted that before I read all the comments. Thanks for all your help man@
@@stevenwhitley6286 Thanks for watching and I hope you or someone can figure this gremlin out. It really sucks for a lot of people for it to not have a fix yet.
A commenter, spikedspike, may have discovered the cause of this issue. I made the linked video hoping to make the possible resolution available to more people: ua-cam.com/video/oGAfw2xpucU/v-deo.html
This is great! I wish I still had the Cobalt. I would definitely go check this out. I don’t recall any oil in the ECM connector when I replaced it but based on the comments by spikedspike you could still have this issue even if you don’t see oil. I hope this resolves the issue for people. It would be great if we start getting comments on your video (well done, btw) or here on whether this fixes it or not.
E cm link
Thanks for watching, Don.
The link for the ECM I bought is in the video description, towards the bottom.
Its replace your BCM body control module!!!!!!!!
Has the problem came back?
Yes, the problem came back after about 6 weeks. I then moved on and replaced the TCM (ua-cam.com/video/Lh-K7NWa6yI/v-deo.html).
It's currently been about 12 weeks since I replaced the TCM and the issue hasn't come back. However it's going to have to be at least 6 months of no issues before I fully declare it fixed.
Thanks for watching!
Just to add another follow-up. After 130 days, the issue came back again. So, after replacing the ECM and TCM, the randomly occurring problem still occurs. So frustrating!
@@CarbonsDIYGarage I have a 2005 cobalt, has been a nightmare lately. I grounded my TCM, with 2 ground wires to shock tower, and still the transmission bucks terribly. However, whenever I add a little 10 W 30 to the 5 W 30, it seems to work ok for a week or so... then the bucking problem returns. I will never buy Chevy, or any American brand, ever again.
@@tomlindroos828 Thanks for watching, Tom! I can't agree more on your assessment. I got this Cobalt for a really good price and boy - I really have to keep that in mind when I deal with this stuff. It's really disheartening how the US brands (well, the GM and Chevy brands in my personal experience) have slipped so much over the past couple of decades.
I hope somehow your Cobalt starts behaving better for you. Good luck!
@@CarbonsDIYGarage The sad thing about the Cobalt is that the mechanicals are great, but the lousy electric modules ruin would could have been a classic Chevy..... so sad. From now on I'm buying Japanese.....
Buy a 1500 car &1000 dollar scanner just my opinion.