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Need some assistance.. Just picked up my 2nd C5.. a 2004. The last owner was not very kind and i have totally replaced the interior and after much work, got the paint looking really good (millennium yellow)..
The other night, I removed the dash pad to correct an issue with the HUD. After fixing it, I replaced the dash pad, started the car to recharge the battery and all was fine...
The next day, I started the car and got throttle body code and it went into REP mode. I have cleaned all the engine grounds and even got a new battery, as the other one was weak..
replaced throttle body which removed the TB code, but now getting p2101 and p1516. Local Corvette repair shop verified with scan tool that the pedal and TB are in Sync. Upon start up does not throw codes... but at 50% throttle the codes return...They also verified all the wires are ok. They are thinking the TAC module went bad. Have a TAC module coming..
Looked at wires under battery tray.. no signs of acid..
What are your thoughts? Does TAC module sound right, or should we be looking at something different?
Unfortunately I can’t diagnose it for you and I “test and don’t guess” so I can’t say why these 2 DTC’s are being thrown…if it’s happening around 50% throttle I’d be using a labscope not a scan tool to see if the signals are dropping out…a DVOM or a scan tools refresh rate is way to slow…has your Corvette shop if they are weak at electrical diagnostics which most normally are followed the flow chart below ??…just because your APP and TPS are in “sync” means nothing…the flow chart below may help them…if you are in Southeast Georgia I can recommend a shop…cleaning the grounds unless they are involved in the TB, TAC Module, and APP circuits doesn’t really accomplish anything.
Tac Module replaced and original codes disappeared... They drove car for 30 minutes.. no issues.. Went to pick it up after sitting for a bit.. started it and REP and now only code P0120 appears
Perhaps the new (Ebay new) throttle body TPS is bad?? They are going to swap throttle body assemblies and TPS tomorrow
Wiring checks out ohms and continuity...
These types of issues drive me crazy.. All that is left is pedal position sensor and ECM....
They are going to go over everything again tomorrow.. I'm confident they will get it.. nothing is easy lol
I'm in the same boat minus the TPS (which I can see working well on the scanner) I just bought a bench power supply so I can pull the APPS out and test it without being upside down and sardine-ified.
At this point I have lost 2 window motors, two door lock controllers, a headlight ballast (that one might have been banging around), now I'm trying to figure out what is bad The TAC, the APPS or the wiring between them .... I figure it's time to learn/invest in DC electronics if I'm going to keep this car.
Codes p2101 and p1516
