Throttle Actuator Control

Some models use a Throttle Actuator Control (TAC) system to electronically calculate and control the position of throttle plate. This eliminates the need for a mechanical cable attachment from accelerator pedal to throttle body. The TAC system consists of an Accelerator Pedal Position (APP) sensor, throttle body assembly, Throttle Actuator Control (TAC) module and PCM. Cruise control functions are also performed by the TAC system. Idle Air Control (IAC) valve is eliminated.

The throttle actuator is an electric motor attached to throttle body and responds to command signals received from the TAC module. As vehicle operator moves accelerator pedal, a signal is sent to the TAC module. A command is then sent to the throttle actuator to adjust throttle plate accordingly. The PCM communicates with the TAC module to monitor values of commanded throttle position to actual throttle position. This is done by monitoring Throttle Position (TP) and APP sensor values. Both values must be within a specified value of each other. A diagnostic trouble code will set if actual throttle position value (TP sensor) does not match commanded throttle value (APP sensor).