Throttle Position Sensor/Switch A Circuit High Input
The throttle position sensor (TPS) is reporting a voltage signal that is abnormally high, indicating the sensor circuit may be shorted to power or the sensor itself is failing. This causes the engine control module to lose accurate throttle position data, affecting fuel injection and ignition timing.
What You Might Notice
- Rough or unstable idle
- High idle speed
- Engine surging or hesitation during acceleration
- Check engine light illuminated
- Possible difficulty starting or stalling
Most Common Causes
- 1
TPS circuit shorted to power
A wiring harness short or damaged insulation in the TPS circuit can cause the signal voltage to read continuously high, triggering the code.
- 2
Faulty throttle position sensor
Internal failure of the TPS potentiometer can cause erratic or stuck high voltage outputs regardless of actual throttle position.
- 3
TPS mounting issue or wear
A loose or improperly mounted TPS can lose electrical contact or develop internal resistance, causing intermittent high signal readings.
- 4
Engine control module (PCM) failure
Rarely, a faulty PCM may misinterpret normal TPS signals or have internal circuit damage causing false high voltage detection.
How to Diagnose It
- 1
Check TPS circuit shorted to power — A wiring harness short or damaged insulation in the TPS circuit can cause the signal voltage to read continuously high, triggering the code.
- 2
Check Faulty throttle position sensor — Internal failure of the TPS potentiometer can cause erratic or stuck high voltage outputs regardless of actual throttle position.
- 3
Check TPS mounting issue or wear — A loose or improperly mounted TPS can lose electrical contact or develop internal resistance, causing intermittent high signal readings.
- 4
Check Engine control module (PCM) failure — Rarely, a faulty PCM may misinterpret normal TPS signals or have internal circuit damage causing false high voltage detection.
How to Fix It
- 1
Inspect and repair TPS wiring harness
Check the TPS connector and wiring for damaged insulation, corrosion, or loose connections. Repair or replace any damaged wires and ensure secure connections at the sensor and PCM.
- 2
Replace faulty throttle position sensor
If inspection reveals the TPS is defective or voltage testing confirms stuck high output, remove and install a new OEM or quality aftermarket TPS, then clear the code and verify operation.
- 3
Secure or remount TPS
Verify the TPS is mounted securely to the throttle body with proper torque specifications. Check for mechanical wear or damage to the throttle shaft that may affect sensor positioning.
- 4
Test and replace PCM if necessary
If TPS and wiring test normal, use a scan tool to verify PCM communication and perform module programming updates. If no software fix resolves the issue, the PCM may require replacement.
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