Throttle/Pedal Position Sensor/Switch "D" Circuit Intermittent
The engine control module detected an intermittent signal from the throttle position sensor (TPS) circuit D, meaning the sensor is sending inconsistent voltage readings. This prevents the PCM from accurately determining throttle position, affecting fuel delivery and spark timing calculations.
What You Might Notice
- Hesitation or stumbling during acceleration
- Black smoke from exhaust, especially during cold startup
- Delayed engine cranking or slow starts
- Rough idle or fluctuating RPM
- Check engine light illumination
Most Common Causes
- 1
Loose or corroded TPS connector
The throttle position sensor connector may have corrosion, moisture, or poor contact causing intermittent signal loss. Inspect and clean the connector terminals.
- 2
Damaged or frayed TPS wiring
The wiring harness from the PCM to the TPS may have breaks, cracks in insulation, or pinched wires causing intermittent opens in the circuit.
- 3
Defective throttle position sensor
The TPS itself may be failing internally, producing inconsistent voltage signals as the throttle moves. The sensor may need replacement.
- 4
PCM programming error or bad PCM
A corrupt PCM calibration or failing PCM module may misinterpret valid TPS signals, though this is less common than sensor issues.
How to Diagnose It
- 1
Check Loose or corroded TPS connector — The throttle position sensor connector may have corrosion, moisture, or poor contact causing intermittent signal loss. Inspect and clean the connector terminals.
- 2
Check Damaged or frayed TPS wiring — The wiring harness from the PCM to the TPS may have breaks, cracks in insulation, or pinched wires causing intermittent opens in the circuit.
- 3
Check Defective throttle position sensor — The TPS itself may be failing internally, producing inconsistent voltage signals as the throttle moves. The sensor may need replacement.
- 4
Check PCM programming error or bad PCM — A corrupt PCM calibration or failing PCM module may misinterpret valid TPS signals, though this is less common than sensor issues.
How to Fix It
- 1
Inspect and clean TPS connector
Locate the throttle position sensor connector near the throttle body. Disconnect it, clean both male and female terminals with electrical contact cleaner, and reconnect firmly. Ensure no corrosion or moisture is present.
- 2
Check and repair TPS wiring harness
Visually inspect the wiring from the PCM to the TPS for cuts, exposed wires, pinches, or routing issues. Repair any damaged insulation with electrical tape or replace the entire harness if severely damaged.
- 3
Replace throttle position sensor
If connector and wiring are good, the TPS is likely failing. Remove the sensor from the throttle body, install a new OEM or quality aftermarket TPS, and calibrate if required by your vehicle's PCM.
- 4
Reprogram or replace PCM
If all sensors and wiring test good, have the PCM reprogrammed by a dealer or reputable shop. If reprogramming fails, the PCM module itself may be defective and require replacement.
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