DTC P0638

DTC P0638

Throttle valve actuator control circuit range/performance problem

DETECTION CONDITION

The PCM compares the actual TP with the target TP when the engine is running. If the difference is more than the specification, the PCM determines that there is a throttle valve actuator control circuit range/performance problem.

Diagnostic support note

This is a continuous monitor (CCM).
The MIL illuminates if the PCM detects the above malfunction condition during the first drive cycle.
FREEZE FRAME DATA (Mode 2/Mode 12) is available.
The DTC is stored in the PCM memory.

POSSIBLE CAUSE

Throttle valve actuator malfunction
- Throttle valve malfunction
PCM malfunction

DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1	VERIFY FREEZE FRAME DATA (MODE 12) HAS BEEN RECORDED Has the FREEZE FRAME DATA (Mode 12) been recorded?	Yes	Go to the next step.
1		No	Record the FREEZE FRAME DATA (Mode 12) on the repair order, then go to the next step.
2	VERIFY RELATED SERVICE BULLETINS AVAILABILITY Verify related Service Bulletins availability. Is any related Service Bulletins available?	Yes	Perform the repair or diagnosis according to the available Service Bulletins. If the vehicle is not repaired, go to the next step.
2		No	Go to the next step.
3	VERIFY RELATED PENDING CODE AND STORED DTC Turn the ignition switch off, then to the ON position (Engine off). Verify the related PENDING CODE and stored DTCs. (See ON-BOARD DIAGNOSTIC TEST ). Are any DTCs present?	Yes	Go to the applicable DTC troubleshooting. (See DTC TABLE ).
3		No	Go to the next step.
4	INSPECT THROTTLE VALVE ACTUATOR Inspect the throttle valve actuator. (See THROTTLE BODY INSPECTION ). Is there any malfunction?	Yes	Replace the throttle body, then go to the next step. (See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION ).
4		No	Go to the next step.
5	VERIFY TROUBLESHOOTING OF DTC P0638 COMPLETED Make sure to reconnect all disconnected connectors. Clear the DTC from the PCM memory using the M-MDS. Drive the vehicle under Freeze frame data (Mode 2) condition. Retrieve the DTC using the M-MDS. Is the same DTC present?	Yes	Replace the PCM, go to the next step. (See PCM REMOVAL/INSTALLATION ).
5		No	Go to the next step.
6	VERIFY AFTER REPAIR PROCEDURE. Perform the "AFTER REPAIR PROCEDURE". (See AFTER REPAIR PROCEDURE ). Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE ).
6		No	DTC troubleshooting completed.