General Information

Engine Control
P2138 Throttle/Pedal Position Sensor/Switch D/E Voltage Correlation - 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 APS is mounted in the accelerator pedal to detect the opening angle of the accelerator pedal. It has 2 sensors to detect the accelerator position and a malfunction of the accelerator position sensor. The ECM judges the current opening angle of the accelerator pedal from APS1&2, and the ECM controls the throttle motor based on these signals.

DTC Description

ECM sets DTC P2138 if the ECM detects output voltage of the APS1 is not proportion to APS2.

DTC Detecting Condition





Diagnostic Circuit Diagram





Signal Waveform & Data

1. IG key ON.
2. Check sensor data as below.




3. Data Analysis