DTC P2108: Throttle Actuator Control Module Problem: General Description

The electronic throttle control system (ETCS) controls the throttle valve opening. The system is composed of the throttle actuator, the throttle valve, throttle position (TP) sensors A and B, the throttle actuator control module, the ETCS control relay, the accelerator pedal position (APP) sensor, and the engine control module (ECM).

The APP sensor is operated via the throttle cable to determine the accelerator opening value when the driver presses the accelerator pedal. The accelerator pedal opening value is converted to a signal in the APP sensor and transmitted to the ECM to compute the target position. The target position signal is then transmitted to the throttle actuator control module. The throttle actuator control module determines the throttle valve target position according to the signal received, and it operates the throttle actuator to move the throttle valve to the target position. The actual throttle valve position is determined by TP sensor A installed in the throttle body.

The CPU in the throttle actuator control module performs self-diagnosis for the ROM, the RAM, and the A/D converter. If internal data is found to be abnormal, a malfunction is detected and the malfunction data is transmitted to the ECM. When the ECM receives the malfunction data from the throttle actuator control module, the ECM detects a malfunction in the throttle actuator control module and stores a DTC. When the ECM monitors the serial signal between the ECM and the throttle actuator control module and these signals do not agree, the ECM detects a malfunction and a DTC is stored.