'03 Z06 - Cruising up the highway tonight 65-70 and the DIC goes nuts, c/e and traction light on, no acceleration. I limp home and try to pull the codes. Only 3 history codes showing:
P1515 Command vs Actual Throttle Position Performance (PCM Module)
C1278 TCS Temporarily Inhibited By PCM
U1064 Loss of Communications with BCM

Half hour later at home, the car starts and runs fine but c/e light is still on.
Car is basically stock but I installed a new air bridge recently.

Anyone have any thoughts what it might be before I have to call the dealer?

 

My '01 coupe was doing this last fall. Codes indicated a problem in the accelerator pedal position sensor/throttle position sensor/TAC (Throttle Actuator Control) module system. After two trips to the dealer (who did nothing) I finally opened up the passenger side wheelhouse area where the TAC module lives, and found a severely nicked and pinched ground wire, along with an incorrect (loose, flopping around), mounting of the module. After repairing the ground and properly securing the module, the problem completely stopped. It was getting to the point that it happened almost every time I drove the car, and on the last day it happened, it did it to me FOUR times.....3 times on the way home from work that night. I don't know what system the ground wire was a part of (my service manuals don't show it to be related to the throttle system), but since it's been trouble-free for over 3 months now, I'm convinced the ground was the culprit. I've read numerous posts from other members that essentially say the same thing: "Check your grounds!" The electronics on these cars are extremely sensitive to faulty grounds.
And BTW, the "Service Engine" light will shut off after the third ignition cycle of the engine.

 

I have the whole weekend to play with it so please point me in the right direction....pass. side wheelhouse area...front under the battery, right?

 

bb609

Before you get too involved with the PCM, there are a few simple things that you can check;

- There have been numerous instances where moisture or water leaking onto the Body Control Module (BCM) cause the dash to go CRAZY! The water can leak on the BCM from a couple of places. Check the BCM and the area around the BCM (Carpet and jute underlayment) and see if it is damp or wet.





Some 97 and eadly 98 models had defective Throttle Control Modules (TAC) and caused the car to go into the limp home mode! Been there!!! You have an 03 so it probably not that.

- The other thing that can cause some weird issues is a loose battery cable.

Recommend clearing the codes and see if it runs better or if the code comes back.

BC

 

Obvious first, right? I guess I should have checked this before even posting (twice...doh!) but I found that I could move the negative cable on my newly installed Optima....hopefully problem solved.

Thanks to all for your advise!

 

Glad you found your problem so quickly (and cheaply!)
BTW, that U1064 is an occasional code that may pop up from time to time. Just like U1016 or U1096. These "U" prefix codes relate to communications between the various on-board computers and usually relate to the "SOH" (State of Health) test communications the PCM sends out over the serial data line each time the car is fired up. You will usually see them with the "H" suffix meaning it's a history code. Sometimes they may have a "C" (current) suffix or sometimes both an "H" and a "C" together.
As long as you don't experience an actual malfunction of some sort, they can be ignored. HTH

 

Thanks. Time to buy a set of manuals.