General Information

Component Location





General Description

The Electronic Throttle Control (ETC) system is made of the components throttle body, Throttle Position Sensor (TPS) 1&2 and Accelerator Position Sensor (APS) 1&2. The throttle body contains the actuator, the throttle plate and the throttle position sensor (potentiometer), which are integrated in one housing. The actuator consists of a DC motor with a two-stage gear. The opening angle of the throttle valve is detected by the throttle position sensor which is mounted on the throttle body. And it provides feedback to the ECM to control the throttle motor in order to control the throttle valve opening angle properly in response to the driving condition.

DTC Description

Checking output signals from TPS under detecting condition, if the difference between real and target throttle position is above the specified value, ECM sets P0638 and then MIL (Malfunction Indication Lamp) turns on.

DTC Detecting Condition





** If Main relay has a fault (ex. Open) under engine running, the DTCs,P0638/P0685/P1295/P2106, can happen at the same time.

- P0638 Throttle Actuator Control Range/Performance (Bank 1)
- P0685 ECM/ECM Power Relay Control Circuit/Open
- P1295 Throttle Actuator Control System-Power Management
- P2106 Throttle Actuator Control System-Forced Limited Power

Diagnostic Circuit Diagram

Signal Waveform & Data

Fig.1) Normal waveform of ETC motor with acceleration
Fig.2) Normal waveform of ETC motor with deceleration