General Information
P0638 Throttle Actuator Control Range/Performance (Bank 1)
General Information
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 PCM 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, PCM sets P0638 and then MIL (Malfunction Indication Lamp) turns on.
Comparing real intake air flow and the intake air flow calculated by ETS under detecting condition, if the air flow more than threshold value is detected for more than 19 sec., PCM sets P0638.
DTC Detecting Condition

** If Main relay has a fault (ex. Open) under engine running, the DTCs, P0638/P0685/P1295/P2110, can happen at the same time.
- P0638 Throttle Actuator Control Range/Performance (Bank 1)
- P0685 PCM/ECM Power Relay Control Circuit /Open
- P2106 Lime Home Mode - Force Limited Power
- P2110 Lime Home Mode - Forced Limited RPM
Specification


Diagnostic Circuit Diagram

Signal Waveform & Data


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