LY6 goes into limp mode

[02blkss]

I have a Ly6 and 4L80e transplanted in a 72 Monte Carlo. The Ly6 has headers, LS3 intake, LS3 injectors, and LS3 MAF. From a standing start when the throttle is bliped in gear the ECM logs a P0606 Control Module Internal Performance ( you can see this in the log at frame 6000). Once I clear the code, turn off and restart the car I get the ETC back. Obviously the tune has room for improvements but it starts idles and drives down the road in a acceptable manner and I never set the P0606 unless I apply aggressive throttle from being completely stopped. What am I missing in diagnosing this problem? Any help would be appreciated.

[Shrek]

What APP (gas pedal) are you using ? Is the wiring harness from the original LY6 vehicle, or an aftermarket product ?

[02blkss]

I am using the recommended corvette pedal GM# 25835421 with a PSI harness.

[flame]

Not sure if your problem is related or not but this guy is having ETC probs with a PSI harness too http://www.hptuners.com/forum/showthread.php?t=37221

[Shrek]

I am using the recommended corvette pedal GM# 25835421 with a PSI harness.

If you are using the LY6 (6.0 L) truck tune in the ECM - it is calibrated for a truck TB and truck APP.

I did an LS7 / 6L90 combination last year - running a truck tune & TB with a Corvette APP. The APP & TB would work just fine together with the engine not running. Once the engine was running, DTCs would set - and the TB would stop working.

Switching to a truck APP solved the problem. If you do experiment with different APPs (Corvette, truck, Trailblazer, van), remember that although they use the same connector - each type is wired differently.

[02blkss]

Flame - Thanks for the pointer but my problems do not seem as severe as the ones referenced in the thread.

Shrek- I have a call in to Jon to verify that the tune I have supports the corvette APP with the truck TB. I would think I would have other issues if it wasn't. Going down the road I can floor the throttle to verify kick down in my 4L80E and all is well. The only time I can create the problem is from a dead stop and it is consistent.

[busta9876]

did you by chance use ''write entire'' on this ecm with a calibration OTHER then what was in it from the factory?

http://www.hptuners.com/forum/showth...ighlight=p0606

[53mercury]

I also transplanted a LY6 from a 08 2500HD and had issues with the vette fuel pedal! I ditched the vette pedal ran the truck pedal and problem solved. May not work for you with psi harness but if you have the truck pedal there plug it in and try it....can't hurt.

[Shrek]

... May not work for you with psi harness but if you have the truck pedal there plug it in and try it ...

Both APPs use the same plug - just need to switch two wires (between Corvette & Truck applications).