Throttle/Pedal Position Sensor/Switch "D" Circuit High
The PCM detected an abnormally high voltage signal from Throttle/Pedal Position Sensor D, indicating a circuit fault between the sensor and engine control module. This causes the engine to enter limp mode with severely restricted acceleration to protect the drivetrain from uncontrolled throttle response.
What You Might Notice
- Severely limited or no acceleration response
- Engine enters limp mode with reduced power
- Stuck throttle at any RPM
- Engine stalling at idle or during light acceleration
- Hesitation when attempting to accelerate
Most Common Causes
- 1
Open or shorted wiring harness
Broken, frayed, or pinched wiring between the throttle position sensor and PCM creates high voltage signal conditions. This is the most common electrical failure affecting this circuit.
- 2
Defective throttle position sensor (TPS) or pedal position sensor (PPS)
Internal sensor failure or resistance drift causes the sensor to send incorrect high voltage signals to the PCM, triggering the fault code.
- 3
Corroded or loose electrical connectors
Oxidation or poor contact at sensor connectors increases resistance and creates erratic high voltage readings that trigger the code.
- 4
Faulty drive-by-wire actuator motor or PCM
A malfunctioning electronic throttle actuator or PCM input circuit malfunction can misinterpret normal sensor signals as high voltage faults.
How to Diagnose It
- 1
Check Open or shorted wiring harness — Broken, frayed, or pinched wiring between the throttle position sensor and PCM creates high voltage signal conditions. This is the most common electrical failure affecting this circuit.
- 2
Check Defective throttle position sensor (TPS) or pedal position sensor (PPS) — Internal sensor failure or resistance drift causes the sensor to send incorrect high voltage signals to the PCM, triggering the fault code.
- 3
Check Corroded or loose electrical connectors — Oxidation or poor contact at sensor connectors increases resistance and creates erratic high voltage readings that trigger the code.
- 4
Check Faulty drive-by-wire actuator motor or PCM — A malfunctioning electronic throttle actuator or PCM input circuit malfunction can misinterpret normal sensor signals as high voltage faults.
How to Fix It
- 1
Inspect and repair wiring harness
Visually inspect the throttle position sensor wiring harness for damage, corrosion, or loose connections. Repair or replace damaged wiring and test voltage readings with a multimeter to confirm proper signal levels.
- 2
Clean or replace sensor connectors
Disconnect the throttle position sensor connector and inspect terminals for corrosion or damage. Clean with electrical contact cleaner or replace the connector if corroded to restore proper voltage signal transmission.
- 3
Replace throttle or pedal position sensor
If wiring and connectors are intact, the sensor itself is likely faulty. Remove and replace the defective TPS or PPS with OEM or quality aftermarket part, then clear the code and test drive.
- 4
Replace drive-by-wire throttle actuator or reprogram PCM
If all sensors and wiring test good, the electronic throttle actuator motor or PCM may be faulty. This requires professional diagnostics and potential component replacement or reprogramming.
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