P0812Powertrain
Powertrain · SAE
Clutch Position Sensor Circuit — Malfunction
Meaning
The TCM has detected an abnormal voltage or resistance in the electrical circuit of the clutch position sensor. The signal is absent, out of range, or implausible relative to other transmission parameters.
Common causes
- Clutch position sensor circuit shorted to ground or to supply voltage
- Open circuit (broken wire or disconnected connector)
- Internal failure of the clutch position sensor
- Corroded connectors or terminals increasing line resistance
- Electromagnetic interference on the sensor signal
- Faulty TCM (rare cause)
Symptoms
- Check engine / transmission warning light on
- Absent or incorrect shifting (transmission in limp mode)
- Harsh or impossible gear engagement
- No clutch position signal visible on the scan tool
- In some cases no perceptible symptoms
Severity
High: without a reliable position signal the TCM cannot manage the clutch correctly, risking mechanical damage or loss of traction.
What to do
- Read fault codes and check for additional DTCs related to the transmission circuit
- Visually inspect wiring and connectors of the clutch position sensor
- Use a multimeter to measure supply voltage, signal voltage, and resistance between sensor and TCM
- Isolate the sensor from the circuit and verify wiring harness integrity
- Replace the sensor if the harness is sound; repair the harness if faults are found