The Accelerator Pedal Position (APP) Sensor is a variable resistor that provides the PCM with an input signal (voltage). The signal represents pedal angle position. As the position of the accelerator pedal changes, the resistance of the APP sensor changes.
Removal & Installation
- Disconnect the negative battery cable.
- Disconnect the electrical connector form the pedal assembly.
- Remove the mounting nuts.
- Remove the pedal assembly from the mounting studs.
- Installation is the reverse order of removal.
- Using a diagnostic scan tool, check for the presence of any Diagnostic Trouble Codes (DTCs). Record and address these codes as necessary.
- If no codes are present, review the scan tool environmental data. If possible, try to duplicate the conditions under which the DTC set.
- If applicable, actuate the component with the scan tool.
- Monitor the scan tool data relative to this circuit and wiggle test the wiring and connectors.
- Look for the data to change, the actuation to be interrupted, or for the DTC to reset during the wiggle test.
- Refer to any Technical Service Bulletins (TSBs) that may apply.
- Turn the ignition off.
- Visually inspect the related wire harness. Disconnect all the related harness connectors. Look for any chafed, pierced, pinched, partially broken wires and broken, bent, pushed out, or corroded terminals.
- Perform a voltage drop test on the related circuits between the suspected component and the Powertrain Control Module (PCM).
- Inspect and clean all PCM, engine, and chassis grounds that are related to the most current DTC.
- If numerous trouble codes were set, use a schematic and inspect any common ground or supply circuits.
- For intermittent Misfire DTCs check for restrictions in the Intake and Exhaust system, proper installation of Sensors, vacuum leaks, and binding components that are run by the accessory drive belt.
- Use the scan tool to perform a System Test if one applies to the component.
- A co-pilot, data recorder, and/or lab scope should be used to help diagnose intermittent conditions.