Darn, I was hoping to watch thru to resolution. I have 2010 malibu. Went thru electrical issues a few years back and brass battery ground fixed it all. Now 5 years later having power steering issues (not just the light) and traction light on. Sorry to hear about the Cobalt's demise, but at least you don't have the problem anymore.
I agree, April, I really wish I'd have been able to figure that out - or at least exhaust every possible option. This is going to be like forever having a song stuck in my head! :) I hope you're able to resolve the traction light and steering issues on your Malibu. Thanks for watching!
THIS IS THE STEP I'M TAKING DUE TO DOORS LOCKING UNLOCKING WHEN IN GEAR ALONG WITH ERRATIC MESSAGES CLUSTER WIGGING OUT AS WELL TRIED CLEANING EVERY GROUND AS THE FORUMS AND VIDEOS SHOW AND ADDING THE GROUND STILL SAME ISSUES WHEN UNPLUGGING TCM ISSUES GO AWAY WIRING LOOKS OK NOT BROKEN OR CHAFED IN THE PROBLEM AREA BY OIL FILTER HOUSING SO I'LL TRY THE TCM NEXT AND SEE WHAT HAPPENS
I was having Trans mission problems and codes said shift solenoid was bad. Replaced all 3 shift solenoids. Problem seemed fixed but now it jumps out of overdrive but doesn't throw any codes. What can this be. 275k miles. Has been a good car
Thanks for watching, James! Certainly can't disagree with you. Can't say I tried turning the car on with the TCM unplugged but I did unplug it/remove battery power to the car quite a number of times, which didn't help. Of course, in my case, replacing the TCM also didn't help... :(
Hello, I just bought a 2010 Cobalt yesterday that doesn't want to shift into first gear. I need to be rolling enough just to catch second gear then it slips for a second then goes to 3rd gear. It drives ok once I get to 4th . If I'm on a hill I'm pretty much Fd if people are behind me. The only code that came up is Power Train System "U0073 -00 control module communicator bus" but there is no engine light on the dash. Do you think this could be the problem hopefully? The guy I bought it from said it just started happening suddenly. Please lmk? Great video and Subbed!
That’s a tough one, Joe! I’m not transmission smart enough to really answer your question. It could be the TCM, wiring, a sensor/module in the transmission, hardware in the transmission, or something else all together. This thread has a couple of things you could easily check. www.chevyhhr.net/forums/problems-service-repairs-42/dtc-p0700-u0073-39743/ After that, my thought is to have a reputable transmission shop try to help you diagnose it, if it’s even a tranny problem. Sorry to not be able to really help on this one. Thanks for watching and subscribing.
If you follow the link to the part that’s in the video description you can confirm that it fits your specific year/make/model. If it doesn’t, contact them. Give them your VIN number and I’m betting they’ll have one that fits your car. Good luck and thanks for watching.
Thanks for watching, Richard. Update from January 2022: I installed this new TCM in June 2021. I went "problem free" until October 2021 - almost long enough to convince myself it was fixed. I cleared the codes and it behaved normally again. I'd pretty much at that point decided I'd just keep a code reader handy and when it does this, just clear the codes and it should resolve the problem for a while. In other words, just live with it. Unfortunately, the car got wrecked (other driver's fault) in December 2021 so we'll never really know if I'd have been able to actually solve this problem. So, sorry, nope - it didn't fix it in the long term. Good luck with yours!
Hi Carbon did the repair in the video last is it still working like it should I been chasing repairs on the cheap and they all hav seemed to have lasted for a very short time. I am going to buy from your information that you put in the description well I hope to hear from you thanks for the video gives me new hope for my cobalt
Thanks for watching, David! I installed the new TCM on June 5, 2021. As of 8/31/21 there have been no reoccurrences of the problem. Given the sporadic nature of when this chooses to happen and then go away "for a while," I feel like need to wait until the end of the year to officially call the problem solved. That said, it's been 87 days with no issues. I wish I could say that this is the definitive fix for all cases but at least for me, so far so good! Good luck!!
@@CarbonsDIYGarage I have a fiy for ya there is some infofrmation to check and fix if needed for maintainence. The G105 is located In the thermostat housing and the G107 In the left rear of the engine block next to the knock sensor From what this person wrote it sounds sensible and here it is: My daughter's 2007 Cobalt had all of these symptoms. Added the ground wire from the TCM case to the chassis. this helped for a while. Shop wanted to replace the TCM, etc... etc... Brought it home instead. Checked all of the ground points, specifically G105, which is the ground for the TCM. It was tight and did not show any corrosion around the connection. Upon a closer look, the wires going into the ground terminal ring were heavily corroded. It wasn't easy to get down there to see, but using my phone I got a decent pic (attached). The wires were corroded and most strands broken - hanging by a thread. Chevy also did a substandard job of strain-relieving. I lightly tugged on the wires and they pulled right out. Note that G105 grounds the ECM and TCM (plus a few other things). I had to clean up the terminal ring and remove the old wiring. I soldered all of the grounds back into the connector and re-attached. No issues since. I am posting because this was a very frustrating problem and shops just want to throw parts at it. Apologies for the subpar photo, but it was difficult to get my phone down there and focus.
I think it needs to be programmed specifically with your car’s VIN. A Chevy dealer might be able to do it for you if you get the same part number from a junk yard. But that’s why I went with the part that I did off eBay: they programmed it with my VIN before they shipped it. Good luck and thanks for watching!
Thanks for watching, Joseph. It gets more complicated than that. I did the ground wires in December 2020 (I think; I didn't write it down). No problems until March, so after nearly 4 months I thought the ground wire did it, but no such luck. I then replaced the battery. That "fix" lasted 1 month until it happened again. Next was the ECM in April 2021 (ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-9oJfU6kQMRo.html). That "fix" lasted 2 months, until it happened again. That's when I replaced the TCM - in June 2021. So it's been 2 months now since this video was recorded. Issue hasn't come back...yet. I think it's going to have to be at least 5-6 months of no issues before I say it was, ultimately, the TCM at fault. The additional grounds certainly can't hurt anything. If it's not the TCM, then I think I've run out parts to throw at it and it becomes a "wiring issue," which would totally suck. The screw/bolt on the TCM is something I supplied as part of the additional grounding of the ECM and TCM to the driver side strut tower ground (you can see that setup in my ECM video, linked in this comment).
@@CarbonsDIYGarage oh no no I just grounded mine and it's working. I just found ur other video and commented on it. I was so hopeful it was fixed. Craiptacular
@@New_trendin_topics If I was you I would go out and buy a TCM module I have had the same problem and by doing the same steps as Carbon and more I thought that if I would buy a programer for modules that I could fix it that way, nothing but bad luck. the wire grounding will only work for a short period of time and there is a chance of it causing more damage Carbon was lucky not to have caused more damage then had happened all of these modules connect to one another. Replace it as soon as possible and make sure it is programed to your VIN number (Vehicle Identification Number) there is nothing more satifying then knowing that your car is up to par with out some jerry rigged fix not knowing or worse forgetting and having it break down again but this time when your 100 miles away from home lots of luck I just had to get this out there!
Thanks for watching! Check out the ebay link in the "Parts" part of the video description. That's how I got my TCM - it's refurbished but they program it for your VIN before they ship it to you. It worked great and very reasonable price.
bought a reprogrammer for my 2009 Chevy cobalt LT and after I programmed a fob to it, my engine light came on. I ran the code reader and got a p0700 code and u0073 code. This makes no sense why it came on right after I did this but it’s been fine. I only have 89k miles. Any help/ideas why please?
My 2010 isn’t shifting from 2nd to 3rd. When it hits 35 mph it won’t shift and just revs up. I’ve been trying to find a video with the same problem but can’t find one. What do you think the problem would be? Thanks for your time
I'm afraid I don't have/know a good answer for you on this one. If you don't have any check engine codes, it might be some type of hydraulic problem in the transmission. You might try to find a transmission shop that will check yours and give you a diagnosis on whether or not it's the transmission. Also, maybe someone will see your comment here and offer a suggestion. Good luck!
Yes. That's why I ordered the part off eBay (link in video description). You provide your VIN and they'll flash it for you before they send it. Thanks for watching.
The TCM needs to be programmed with your vehicle’s VIN but doesn’t need to be new. The link in the video description is where I got the used TCM that they programmed to my VIN. It worked great for as long as I owned the car. I hope that helps. Thanks for watching.
Hey there. Having similar issues,no speedometer,power steering on dash..won’t shift….I tried cleaning the grounds from the TCM and a couple other things I seen online..I’m down to being convinced it’s the TCM itself. If I was to buy one online or from eBay do I have to have a dealer flash it? I’m just worried about buying a tcm and it not working because it’s not flashed or something along those lines…any info/advice helps. Thank you.
Thanks for watching, Tommy. No need to take it to the dealer. It does need to be VIN matched/programmed, though. For the one I bought off eBay, I provided the VIN in my order and they programmed it before they sent it. It works great. I hope that helps. Good luck with this very frustrating issue.
@@cobaltcobalt463 I bought a tcm and replaced it and it still did not fix it…what ended up being wrong was the speed sensor was cut! It had all the same symptoms as if the tcm and other stuff goes..but it ended up being a $20 part from autozone,very easy to get to. Behind the passenger tire…check the speed sensor! Hope this helps! I’m curious to know if that’s what it was!
@@tommybest4639 Appreciate the comment. Situation: Speedometer not engaging, transmission not changing gears based 2nd. Power steering dash light (cleared by mechanic), no power steering (very loose feeling, no handling) I went to a mechanic when I first had this issue and he said it was a speed sensor. But I declined for them to fix it because they quoted it as including it as a lot of work; hence DIY. I will try that next, before installing the new TCM; purchased a TCM from the ebay shop where they preprogram and it will arrive Monday. Change: 10/9/22 - Installed a ground wire to TCM - no change in power steering / speedometer / transmission engaging issue.
@@cobaltcobalt463 awesome hopefully the new TCM works…I also put a ground to the tcm..including the new tcm that I purchased and it did nothing…the speed sensor is a whole seperate part it’s easy to get to behind the passenger front tire,you can access it from under the hood or if you take your tire off…I think it takes a size 10mm bolt…it’s just 1 bolt I believe..but I swapped that out and everything works great…I will say if the wires are damaged you might have to go to a junkyard to get the replacement wires…Napa,auto zone,advance auto parts etc. did not have the wires…but they did have the speed sensor…one other thing,when I put in my new TCM my cobalt did drive normal for about 5 minutes and then it immediately went back to all the same issues..best of luck!! Hope you get it fixed.
I haven't gone through the process myself; I got a VIN-matched TCM off eBay. But when I replaced the ABS controller module on my Jeep JKU, I took the vehicle (with module installed) to the dealer and the reflashed it - only the dealer was able to do it. I'm not sure if the car will start with the non-VIN matched TCM installed so maybe call your local dealer's service department and ask them if they can flash it for you (and how much it would cost).
Necessary? I don't really know. I took the mental approach of the fact that they both SHOULD be grounded. If there's a grounding problem in either of them, hooking them to an alternate ground can only improve things. I saw doing both of them as "do no harm." It also meant I didn't have to experiment with just one, just the other, and then both. Thanks for watching!
I just bought a tcm tried replacing it car turned on just fine but the gear shift didn’t wanna budge and when I put the old one back on it allow me to shift the gear. Idk what to do because my car has been having a spaz attack where it would stutter when I accelerate or brake, I hear a clicking sound in the gear shift, my mph/rpm/gas gauge freak out, my electronic power steering goes out making the steering wheel hard to turn. My error codes are P0700 and U0073.
Sorry to hear about your woes. The only question that comes to my mind is if you got the new TCM matched/programmed to your VIN. That’s the only reason that comes really to mind on why it won’t let you shift out of park with the new one. After that, I’m out of ideas. Maybe others will comment with a solution though! Thanks for watching!
Thanks for watching and asking, Jonathan. I installed this new TCM in June 2021. I went "problem free" until October 2021 - almost long enough to convince myself it was fixed. I cleared the codes and it behaved normally again. I'd pretty much at that point decided I'd just keep a code reader handy and when it does this, just clear the codes and it should resolve the problem for a while. In other words, just live with it. Unfortunately, the car got wrecked (other driver's fault) in December 2021 so we'll never really know if I'd have been able to actually solve this problem.
@@Azaanali190 I just use this simple (and inexpensive) code reader. Works great for my needs of just reading and resetting codes. Probably (unfortunately) one of my most frequently used tools. amzn.to/3IiqJ4Q
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: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-oGAfw2xpucU.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.
@@CarbonsDIYGarage I'm crossing my fingers this is the problem. I'll post a new comment on my video if I go problem free for three months, or if the issue returns at any point in the future. Thanks for making your videos by the way. At the very least it might have saved me some money by not buying a new ECM and TCM myself.
@@BoomerElectronics Thanks for watching and keeping us updated. I'm glad I could do at least a little bit to help folks further work on this issue (or at least not waste their $).
@@christianbeland2770 I got it off ebay. Seller was "deeringssales." I updated the link in the video description; the link I had previously no longer works. www.ebay.com/itm/194936227704
You are definitely not wrong. I grew up in a GM family and have owned a few myself and the quality just seemed to go down and the problems go up. The Cobalt was for sure our last. Thanks for watching, Tom.
