I am working on a 05 Isuzu NPR with 6L GM drivetrain. Both the pedal sensor and the throttle body have been substituted. The wiring was tested and each wire bypassed. Extensive testing shows that the TAC module is outputting a higher bias voltage on throttle sensor 1 vs sensor 2. This causes the throttle to lockout (P2135)when the accelerator is pushed about 3/4 travel, running or not. The scope shows that the sensor voltages start out together and get farther apart as the throttle opens. That same voltage difference is on the sensor input leads of the TAC with the throttle unplugged. It is a GM TAC module.

So does a new TAC module need to be programmed to the truck and if so does it require Isuzu or can a GM program it?

thanks

Steve Park
Technician
Public Safety Radio
Gallatin, Tennessee, USA