Diesel Data: Automotive Repair

Advanced Diagnostics

Advanced Diagnostics

DTC P2101: Electronic Throttle Control System (ETCS) Malfunction







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 ETCS control relay, the accelerator pedal position (APP) sensor, and the engine control module (ECM)/powertrain control module (PCM). When the driver presses the accelerator pedal, the APP sensor reacts and detects the accelerator opening value. The accelerator pedal opening value is converted to a signal in the APP sensor and transmitted to the ECM/PCM to compute the target position.The ECM/PCM 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 sensors A and B installed in the throttle body. The ECM/PCM compares the throttle valve target opening angle and the actual throttle valve opening angle from TP sensors A and B, and when the difference exceeds the specification, the ECM/PCM detects the malfunction of the throttle actuator system and a DTC is stored.

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







Enable Conditions







Malfunction Threshold







Diagnosis Details

Conditions for illuminating the MIL
When a malfunction is detected, the MIL comes on and the DTC and the freeze frame data are stored in the ECM/PCM memory.

Conditions for clearing the MIL
The MIL will be cleared if the malfunction does not recur during three consecutive trips in which the diagnostic runs. The MIL, the DTC, and the freeze frame data can be cleared by using the scan tool Clear command or by disconnecting the battery.