Accelerator Pedal Position Sensor: Testing and Inspection

ACCELERATOR POSITION SENSOR (APS)

INSPECTION




FUNCTION AND OPERATION PRINCIPLE
Accelerator Position Sensor (APS) is installed on the accelerator pedal module and detects the rotation angle of the accelerator pedal. The APS is one of the most important sensors in engine control system, so it consists of the two sensors which adapt individual sensor power and ground line. The second sensor monitors the first sensor and its output voltage is half of the first one. If the ratio of the sensor 1 and 2 is out of the range (approximately 1/2), the diagnostic system judges that a malfunction has occurred.

Specification:

Circuit Diagram:

COMPONENT INSPECTION
1. Connect a scantool on Diagnosis Link Connector (DLC).

Specification:

2. Start engine and check output voltages of APS 1 and 2 at C.T and W.O.T.
3. Turn ignition switch OFF and disconnect the scantool from the DLC.
4. Disconnect APS connector and measure resistance between APS terminals 4 and 5 (APS 1).

Specification: Refer to SPECIFICATION.




5. Disconnect APS connector and measure resistance between APS terminals 1 and 6 (APS 2).

Specification: Refer to SPECIFICATION.