Advanced Diagnostics

Advanced Diagnostics

DTC P2176: Throttle Actuator Control System Idle Position Not Learned







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 transmits a signal to the throttle actuator and moves the throttle valve to the fully closed position to register the throttle valve fully closed position after the ignition switch is turned to ON (II). The ECM/PCM detects the malfunction when the registration of the throttle valve fully closed position is not completed within a predetermined time or the registered value is out of predetermined range after the ignition switch is turned to ON (II). The ECM/PCM detects a malfunction in the throttle actuator control system and stores a DTC.

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







Enable Conditions







Malfunction Threshold
One of these condition must be met for at least 0.7 second.
- The registration of the throttle valve fully closed position is not completed within a predetermined time after the ignition switch is turned to ON (II).
- The registered value of the throttle valve fully closed position is 0.74 V*1, 1.61 V*2 or more, or 0.49 V*1, 1.37 V*2 or less.

*1: TP sensor A
*2: TP sensor B

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.