P2138-ACCELERATOR PEDAL POSITION SENSOR 1 / 2 CORRELATION

For a complete wiring diagram Refer to Section 8W

Theory of Operation

The Accelerator Pedal Position Sensor contains two independent three wire sensors. Each sensor provides independent pedal position signals to the ECM. The raw voltage signal from APP 1 sensor is 2 times the raw voltage signal from APP 2. Although the raw voltage signals differ, the scan tool converts and displays these voltages as matching percentages of pedal travel.

• When Monitored:

  With the ignition on. No other APP DTC's set. No Sensor Reference Voltage DTC's set.

• Set Condition:

  APP Sensor 1 and APP Sensor 2 signals do not agree for 0.26 seconds.

Diagnostic Test

NOTE: If any Sensor reference or supply voltage DTCs are present, perform the applicable diagnostic procedure before continuing with this test.

NOTE: The APP Sensor is a device that contains two separate potentiometer type sensors. Each sensor has its own 5-volt supply circuit, sensor ground circuit and signal circuit. The APP Sensor no longer incorporates a low-idle switch.

NOTE: The APP Sensor 2 signal should always be approximately 1/2 the voltage of the APP Sensor 1 signal.

• Replace the Accelerator Pedal Position Sensor.