C 2500 Truck 2WD V8-8.1L VIN G (2002)
Accelerator Pedal Position (APP) Sensor
The APP sensor is mounted on the accelerator pedal assembly. The APP is actually 3 individual accelerator pedal position sensors within one housing.
Three separate signal, low reference, and 5.0-volt reference circuits are used to connect the APP and the TAC module. The APP sensor 1 voltage
should increase as the accelerator pedal is depressed, from below 1.0 volt at 0 percent pedal travel to above 2.0 volts at 100 percent pedal travel.
APP sensor 2 voltage should decrease from above 4.0 volt at 0 percent pedal travel to below 2.9 volts at 100 percent pedal travel. APP sensor 3
voltage should decrease from above 3.8 volts at 0 percent pedal travel to below 3.1 volts at 100 percent pedal travel.
Throttle Body Assembly
Throttle Body Assembly
The throttle body for the TAC system is similar to a conventional throttle body with a couple of exceptions. One exception being the use of a motor to
control the throttle position instead of a mechanical cable. The other exception is the new design Throttle Position (TP) sensor. The TP sensor mounts
on the side of the throttle body opposite the throttle actuator motor. The TP sensor is actually 2 individual TP sensors within one housing. Separate
signal, low reference, and 5.0-volt reference circuits are used to connect the TP sensors and the TAC module. The TP sensor 1 signal voltage
increases as the throttle opens, from around 1.0 volt at 0 percent throttle to above 3.5 volts at 100 percent throttle. TP sensor 2 signal voltage
decreases as the throttle is opened, from around 3.8 volts at 0 percent throttle to below 1.0 volt at 100 percent throttle.
Throttle Actuator Control (TAC) Module
