General Information

Engine Control
P2138 Accelerator Position Sensor 1 & 2 Signal Voltage Correlation - 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. The PCM controls the throttle motor to open and close the throttle valve. The TPS provides feedback to the PCM to control the throttle motor in order to control the throttle valve opening angle properly in response to the driver's demands. The APS is mounted on the accelerator pedal assembly to to send the driver's demand to the PCM. It has 2 sensors to detect the accelerator position. The PCM uses the signals from APS1&2, and controls the throttle motor based on these signals.

DTC Description

Checking output signals from APS 1 and 2 under detecting condition, if output signals difference between APS 1 and 2 are detected more than 4.5% for the specified number of times., PCM sets P2138.

DTC Detecting Condition





Specification





Diagnostic Circuit Diagram





Signal Waveform & Data








Fig.1) Normal waveform and data of APS1 & APS2 with no acceleration
Fig.2) Normal waveform and data of APS1 & APS2 with acceleration
Signal waveform of APS 1 & 2 shows that APS 2 increases voltage just half of APS 1 voltage increase when accelerating.