P0808

What it means

P0808 is the generic code for Clutch Position Sensor A Circuit High. The control unit saw a signal voltage from the clutch position sensor that stayed above the expected range, which usually points to a short to voltage, an open circuit that lets the signal float high, or a faulty sensor. The exact sensor type, location and voltage range depend on the make, model and gearbox.

Symptoms

• Engine will not crank or only cranks with the clutch pedal pushed in fully or in a particular way
• Stop-start system not working or disabled
• Cruise control not working
• Poor or inconsistent idle or throttle response when changing gear or pulling away
• Warning light on the dashboard, with the fault stored in the engine or transmission control unit
• Hill-start assist not working, on cars with that feature

Possible causes

• Faulty clutch position sensor (internal fault giving a high signal)likely
• Damaged, chafed or corroded wiring or connector at the sensorlikely
• Signal wire shorted to a voltage supply or open circuit in the signal or ground wirelikely
• Sensor out of adjustment, or the mounting or pedal linkage worn or brokenpossible
• Poor earth connection shared by the sensor circuitpossible
• Fault inside the control unit that reads the sensorrare

How to diagnose

1. Read all stored codes and freeze frame data, and note whether the fault is current or intermittent
2. Check for other related codes such as clutch switch, starter or battery supply faults that may point to a shared cause
3. Visually inspect the sensor, its connector and the wiring for damage, water ingress, corrosion or rubbing
4. Check the pedal assembly and sensor mounting for wear, looseness or incorrect positioning, as the procedure depends on the model
5. With live data, watch the clutch position reading while pressing and releasing the pedal and see if it sticks high or jumps
6. Unplug the sensor and check the supply, signal and earth with a multimeter against the manufacturer's specification for that model
7. Test the signal wire for a short to voltage and check wiring continuity back to the control unit
8. Check the sensor's own resistance or output across its range if the manufacturer gives figures

How to fix

• Replace the clutch position sensor if its output is stuck high or outside specification
• Repair or replace damaged wiring and clean or renew corroded connector terminals
• Fix any short to voltage or open circuit found in the signal or earth wire
• Correct the sensor mounting or adjustment, and repair worn pedal parts as the model requires
• Repair poor earth connections
• Once other causes are ruled out, have the control unit checked and replaced or repaired if faulty

Can I keep driving?

Nearby codes

• P0807GenericClutch Position Sensor A Circuit Low
• P0809GenericClutch Position Sensor A Circuit Intermittent