Throttle/Pedal Position Sensor/Switch "F" Circuit High
The PCM detected an abnormally high voltage signal from the Throttle Position Sensor/Switch F circuit, indicating a possible open circuit, short to voltage, or sensor failure. This causes the engine to enter limp mode with severely restricted acceleration as a safety measure.
What You Might Notice
- Engine stuck at high idle RPM
- Severely limited or no acceleration response
- Engine stalling at idle
- Hesitation or jerking during acceleration
- Limp mode activation with reduced power
Most Common Causes
- 1
Open or shorted throttle position sensor circuit
A break in the wiring harness or internal sensor malfunction causes the PCM to read an out-of-range high voltage signal from the throttle sensor.
- 2
Defective throttle position sensor (TPS) or pedal position sensor (PPS)
The sensor itself has failed internally or its potentiometer is producing incorrect voltage signals to the PCM.
- 3
Corroded or loose electrical connectors
Poor connections at the sensor harness or PCM connector create high resistance, causing voltage spikes or unstable signal readings.
- 4
Faulty drive-by-wire actuator motor or PCM
The electronic throttle control module or engine control unit may be malfunctioning and misinterpreting sensor signals.
How to Diagnose It
- 1
Check Open or shorted throttle position sensor circuit — A break in the wiring harness or internal sensor malfunction causes the PCM to read an out-of-range high voltage signal from the throttle sensor.
- 2
Check Defective throttle position sensor (TPS) or pedal position sensor (PPS) — The sensor itself has failed internally or its potentiometer is producing incorrect voltage signals to the PCM.
- 3
Check Corroded or loose electrical connectors — Poor connections at the sensor harness or PCM connector create high resistance, causing voltage spikes or unstable signal readings.
- 4
Check Faulty drive-by-wire actuator motor or PCM — The electronic throttle control module or engine control unit may be malfunctioning and misinterpreting sensor signals.
How to Fix It
- 1
Inspect and repair wiring harness
Check the throttle position sensor circuit wiring for breaks, pinches, or exposed conductors between the sensor and PCM. Repair or replace damaged sections and ensure all connections are secure.
- 2
Replace throttle position sensor or pedal position sensor
Remove the malfunctioning sensor from the throttle body or accelerator pedal assembly and install a new OEM or quality aftermarket replacement, then retest.
- 3
Clean and reconnect electrical connectors
Disconnect the sensor harness connector and PCM connectors, clean corrosion with an electrical contact cleaner, apply dielectric grease, and firmly reconnect to restore signal integrity.
- 4
Test or replace PCM/ECU
If all sensors and wiring check out, use a diagnostic scan tool to verify PCM behavior. If the PCM is faulty, it may require reprogramming or replacement by a dealer.
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