Ford Mustang 1999-2005

Accelerator Pedal Position Sensor


Description & Operation

The APP sensor is an input to the Powertrain Control Module (PCM) and is used to determine the torque demand. There are 3 pedal position signals in the sensor. Signal 1, APPS1, has a negative slope (increasing angle, decreasing voltage) and signals 2 and 3, APPS2 and APPS3, both have a positive slope (increasing angle, increasing voltage). During normal operation APPS1 is used as the indication of pedal position by the strategy. The 3 pedal position signals make sure the PCM receives a correct input even if 1 signal has a concern. There are 2 reference voltage circuits and 2 signal return circuits for the sensor.

Removal & Installation

  1. Disconnect the battery ground cable.
  3. Disconnect the accelerator pedal motor electrical connector.
  5. Remove the two bolts and the accelerator pedal assembly.
    1. To install, reverse the removal procedure.



Check the APP Sensor signal output voltage ranges for the accelerator pedal fully applied and released positions.

Click image to see an enlarged view

Fig. Accelerator Pedal Position Sensor connector

APPS1 (Pin #2)

APPS2 (Pin #5)

APPS3 (Pin #8)

Monitor the voltage readings between pins APPS1, APPS2, APPS3, and body ground.
Press the accelerator pedal fully to the floor and release.

After clearing an APP sensor Diagnostic Trouble Code (DTC) to verify a repair or an intermittent concern, apply the accelerator pedal before carrying out the self-test. Take 10 seconds to carry out a full sweep of the accelerator pedal from fully released to fully applied and back to fully released.

APP Sensor Pin Testing

For reference values, refer to PCM testing-PCM reference voltage pin chart This pinpoint test is intended to diagnose the following:

Accelerator Pedal Position (APP) sensor (9F836)
Harness circuits: ETCRTN, SIGRTN, ETCREF, APP1, APP2, and APP3
Powertrain control module (PCM) (12A650)

Click image to see an enlarged view

Fig. APPS connector view