This is a 2010 Tahoe z71 package that I am doing independent work on.
It has 193k Miles, so I would expect E-Tcase issues to happen at this point in time, and when the failure occurs, it would mean multiple failures.
Initially I had done a Tcase service and transmission fluid change. Took on test drive and when switching from 4auto to 4 hi, service four wheel drive light would come on. Unplugged position sensor and re plugged it and it started working again. Get a callback 2 months later saying that the vehicle will not move, but they turned it off and on again and all of a sudden it started moving. Found TSB for the Tcase actuator motor, so I replaced it. That did not work. It does not even attempt to shift from 4 hi to 2 hi. Told her that I do not have a scanner that will pick up the codes, go to the dealership/ another shop because I am beyond stumped. Chevy found that the new motor was internally shorted (weird), but they also couldnt find the exact issue, it sat at their shop for 3-4 days. Replace the New Napa motor for a Dorman, and by this time my new code reader arrived (carly). Dealership provided me with 14 codes
C0306 S-T-G and High Voltage/Open
C0321 Open
C0392 PFmance- Signal invalid
C0396 High voltage/open
B0790 Low voltage/open
B2725 Performance sig invalid
U0101 Invalid data
C0387 Protection Time out
C0398 Not plausible
U0101 Lost com with TCM
C0242 PCM indicated traction control
B0000 Not plausible
Now I know this is a lot, but with the carly scanner I know it can pick up the BCM codes, U series codes. Do I NEED GM data link to be able to read all of those codes? If so the carly was a waste of money. If not, and the carly is picking up every existing code (dealership cleared codes and sent it back), then its only picking up a U0140, lost communication with BCM. BCM still sends highspeed lan and lowspeed lan, so the BCM is intact (albeit maybe not in its full form). Still displays service 4 wheel drive and does not attempt to shift from 2hi to 4hi/4low when requested to. I have a 08 personal tahoe that has this issue intermittently whenever I am doing dumb stuff like drifting in the rain. It throws the same exact code but goes away whenever I clear it and then allows it to shift from 2hi to 4hi. So to me this may just be a loose wire in a pin or a break in the wire. Chevy is stumped, I am stumped, maybe someone has had this issue before? Thanks.
It has 193k Miles, so I would expect E-Tcase issues to happen at this point in time, and when the failure occurs, it would mean multiple failures.
Initially I had done a Tcase service and transmission fluid change. Took on test drive and when switching from 4auto to 4 hi, service four wheel drive light would come on. Unplugged position sensor and re plugged it and it started working again. Get a callback 2 months later saying that the vehicle will not move, but they turned it off and on again and all of a sudden it started moving. Found TSB for the Tcase actuator motor, so I replaced it. That did not work. It does not even attempt to shift from 4 hi to 2 hi. Told her that I do not have a scanner that will pick up the codes, go to the dealership/ another shop because I am beyond stumped. Chevy found that the new motor was internally shorted (weird), but they also couldnt find the exact issue, it sat at their shop for 3-4 days. Replace the New Napa motor for a Dorman, and by this time my new code reader arrived (carly). Dealership provided me with 14 codes
C0306 S-T-G and High Voltage/Open
C0321 Open
C0392 PFmance- Signal invalid
C0396 High voltage/open
B0790 Low voltage/open
B2725 Performance sig invalid
U0101 Invalid data
C0387 Protection Time out
C0398 Not plausible
U0101 Lost com with TCM
C0242 PCM indicated traction control
B0000 Not plausible
Now I know this is a lot, but with the carly scanner I know it can pick up the BCM codes, U series codes. Do I NEED GM data link to be able to read all of those codes? If so the carly was a waste of money. If not, and the carly is picking up every existing code (dealership cleared codes and sent it back), then its only picking up a U0140, lost communication with BCM. BCM still sends highspeed lan and lowspeed lan, so the BCM is intact (albeit maybe not in its full form). Still displays service 4 wheel drive and does not attempt to shift from 2hi to 4hi/4low when requested to. I have a 08 personal tahoe that has this issue intermittently whenever I am doing dumb stuff like drifting in the rain. It throws the same exact code but goes away whenever I clear it and then allows it to shift from 2hi to 4hi. So to me this may just be a loose wire in a pin or a break in the wire. Chevy is stumped, I am stumped, maybe someone has had this issue before? Thanks.
