Multiple error messages - possibly a bad TAC?
Thread Starter
Pro
Joined: Aug 2014
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From: Michigan
Multiple error messages - possibly a bad TAC?
Hey all,
2003 coupe with no mods. Twice last year I got multiple error messages: Reduced Engine Power, Service Active Handling, and Service Traction System. The codes cleared but I knew I needed to keep an eye on it.
Just now I took it out of storage for my first ride. I lost count how many times the same error messages came up. I managed to keep clearing them long enough to turn around and get it home. The Service Traction Control code never cleared, though.
Codes are as follows:
PCM: P1220, P1221, P1280, and P1281
TCM: C1278
From what research I have done, I have the following questions:
1. Do all of these codes mean I need to change the TAC?
2. I have found multiple part numbers for a TAC. What is the current one?
3. Does changing a TAC require a Tech 2 or any sort of calibration?
I’m handy enough to pull the passenger wheel and change the TAC but if a Tech 2 is needed then I’m going to have to take it somewhere.
Thanks in advance,
Jerry
2003 coupe with no mods. Twice last year I got multiple error messages: Reduced Engine Power, Service Active Handling, and Service Traction System. The codes cleared but I knew I needed to keep an eye on it.
Just now I took it out of storage for my first ride. I lost count how many times the same error messages came up. I managed to keep clearing them long enough to turn around and get it home. The Service Traction Control code never cleared, though.
Codes are as follows:
PCM: P1220, P1221, P1280, and P1281
TCM: C1278
From what research I have done, I have the following questions:
1. Do all of these codes mean I need to change the TAC?
2. I have found multiple part numbers for a TAC. What is the current one?
3. Does changing a TAC require a Tech 2 or any sort of calibration?
I’m handy enough to pull the passenger wheel and change the TAC but if a Tech 2 is needed then I’m going to have to take it somewhere.
Thanks in advance,
Jerry
Moderator, Tech Contributor
Joined: Sep 2013
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From: Cape Coral, Florida
If you don’t have any electrical diagnostic experience find an auto electric shop in your area as they are better than a general repair shop or dealership in finding out what’s wrong…trouble codes are not part numbers.
Thread Starter
Pro
Joined: Aug 2014
Posts: 717
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From: Michigan
I’ve seen many posts across multiple forums and varying age (some threads are way over 10 years old) seeming to point to a bad TAC as the root cause for the codes I posted. Just looking for verification that may be the case before I try to hunt a TAC down.
Which leads to my question about what is the right GM part number for a TAC?
If these codes aren’t a silver bullet for a bad TAC, then I’ll definitely have to take it somewhere as you suggested. I was just thinking if it was something as simple as swapping out a module I could do it myself.
Thanks
Thread Starter
Pro
Joined: Aug 2014
Posts: 717
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From: Michigan
This may sound kind of stupid, but further reading points to either a TAC, a TPS, an APP, or a wiring problem.
A shop would charge a small fortune. From what I’m seeing I could get all three parts for around $800.
Would it be insane to just swap all three parts out and inspect the wiring while I’m doing so? From what I’ve seen all three parts look to be relatively easy to swap out.
A shop would charge a small fortune. From what I’m seeing I could get all three parts for around $800.
Would it be insane to just swap all three parts out and inspect the wiring while I’m doing so? From what I’ve seen all three parts look to be relatively easy to swap out.
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,615
Likes: 4,062
From: Cape Coral, Florida
A competent diagnostic shop with the right equipment like a labscope can diagnose this in probably an hour unless there is some wiring inspections to be done and you’ll only have to replace one part not 3.
