General Information
Engine
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 PCM judges the current opening angle of the accelerator pedal from APS 1&2, and the PCM 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. And then MIL (Malfunction Indication Lamp) turns on.
DTC Detecting Condition
Specification
Diagnostic Circuit
Signal Waveform
Fig.1) This is a signal waveform of APS 1 & 2 which shows that APS 2 increases voltage just half of APS 1 voltage increase when acceleration.