General Information

Engine Control
P0638 Throttle Actuator Control Range/Performance (Bank 1) - General Information

Component Location





General Description

The Electronic Throttle Control (ETC) system consists of the throttle body, Throttle Position Sensor (TPS) 1 & 2 and Accelerator Position Sensor (APS) 1 & 2. TPS 1 & 2 share the same source voltage and ground. The PCM controls the throttle motor to open and close the throttle valve. The TPS1 output voltage increases in proportion with the throttle valve opening angle after starting. TPS2 output voltage decreases in proportional with the throttle valve opening angle after starting. The TPS provides feedback to the PCM to control the throttle motor in response to the APS.

DTC Description

PCM monitors output signal from TPS. If the difference between real and target throttle position is above the specified value, the PCM sets a P0638 DTC and illuminates the Malfunction Indicator Lamp (MIL).
Comparing real intake air flow and the intake air flow calculated by ETS, if the air flow is more than threshold value for more than 19 seconds the PCM sets a P0638 DTC.

DTC Detecting Condition





**If the Main relay is inoperable with engine running, the following DTCs can set.

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

Specification

Diagnostic Circuit Diagram

Signal Waveform & Data

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