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 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

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., ECM sets P2138. And then MIL (Malfunction Indication Lamp) turns on.

DTC Detecting Condition





Specification





Diagnostic Circuit Diagram





Signal Waveform & Data




















Fig 1) Normal waveform of TPS1 & TPS2 with no accel pedal depressed under IG ON condition
Fig 2) Normal waveform of TPS1 & TPS2 with accel pedal depressed under IG ON condition
Fig 3) Normal data of TPS1 & TPS2 under IG ON condition
Fig 4) Normal data of TPS1 & TPS2 under open condition
Fig 5) Normal data of TPS1 & TPS2 under short to ground in TSP2 circuit