General Information

Engine

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 APS 1&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 APS 1 & APS 2 with no acceleration
Fig.2) Normal waveform of APS 1 & APS 2 with acceleration
Fig.3) Normal data of APS 1 & APS 2 at ig on.
Fig. 4) Abnormal data of APS 1 & APS 2 when APS 1 & APS 2 circuit open

Signal waveform of APS 1 & 2 shows that APS 2 increases voltage just half of APS 1 voltage increase when accelerating.