Advanced Diagnostics

Advanced Diagnostics - DTC P2108: Throttle Actuator Control Module Problem






General Description
The electronic throttle control system 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 throttle actuator control module relay, the accelerator pedal position (APP) sensor, and the powertrain control module (PCM). When the accelerator pedal is pressed, the APP sensor detects the accelerator opening value. The accelerator pedal opening value is converted to a signal in the APP sensor and transmitted to the PCM 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 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 PCM. When the PCM receives the malfunction data from the throttle actuator control module, the PCM detects a malfunction in the throttle actuator control module and stores a DTC. When the PCM monitors the serial signal between the PCM and the throttle actuator control module and finds these signals do not agree, the PCM detects a malfunction and stores a DTC.

Monitor Execution, Sequence, Duration, DTC Type, OBD Status






Enable Conditions






Malfunction Threshold
One of these conditions must be met for at least 200 milliseconds.
- Data read from the ROM is abnormal.
- Data read from the RAM is abnormal.
- The A/D converter standard voltage is out of specified value.
- The serial signals between the PCM and the throttle actuator control module do not agree.

Diagnosis Details

Conditions for setting the DTC
When a malfunction is detected, the MIL comes on and a Pending DTC, a Confirmed DTC, and the freeze data are stored in the PCM memory.

Conditions for clearing the DTC
The MIL is cleared if the malfunction does not return in three consecutive trips in which the diagnostic runs. The MIL, the Pending DTC, the Confirmed DTC, and the freeze data can be cleared with the scan tool Clear command or by disconnecting the battery.