The project in my sig is done but still will not start. I have the factory TAC module, pedal assy and harness from the pedal to the TAC module as well as the factory 2005 PCM. My harness is the only thing that is not factory, and I believe there is a wire crossed that is giving me this APP code. The PCM thinks the throttle blade is at like 19 degrees, but it actually remains closed. The truck will start and run for about 3-10 seconds and then fall on it's face from dumping tons of fuel. If anyone has this diagram please help me here. This is my daily driver, and it is killing me not to have this thing running right now. Thanks in advance.

Chris

 

An APP code would result from a problem between the pedal and TAC module, or possibly low system voltage or a poor ground to the firewall. A problem between the TAC module and TB would result in TP codes.

The TAC module just relays this info to the PCM via a serial data line.( 1 in , 1 out)

Are you using the correct tune for your model/year?

19% TP is the spring determined position when the TAC motor is de-activated, such as when a fault condition is triggered or the key is off, or the key is on but the engine has not been started within X seconds. The blade will appear to be just slightly cracked open.

 

how does the TAC ground to the firewall? From its mounting?

 

Black wire on pin 15 of the 16 pin connector. Ties in with G104 circuit which is the ground from the rear of the drivers side cylinder head to the firewall.