P08B7
Clutch Pedal Position Sensor B Circuit High.
- Generic
- Powertrain
- Generic code
- Medium severity
How this code is built
- P
- SystemPowertrain
- 0
- Defined bySAE, the same on every car
- 8
- AreaTransmission
- B7
- FaultThe specific fault in that area
What it means
P08B7 is a generic powertrain code meaning the control unit has detected a high voltage or signal level on the circuit for clutch pedal position sensor B. The module sees a reading above the expected range, which usually points to an open circuit, a short to voltage, or a faulty sensor. Exact sensor type, wiring and strategy vary by model and engine, so check the manufacturer data for your vehicle.
Symptoms
- Engine warning light on
- Engine will not start or only starts when the clutch is pressed hard or at a certain point
- Start/stop system disabled or behaving erratically
- Cruise control not working
- Poor or erratic idle, stalling or hesitation when pulling away on some models
- Gear change or torque management feels odd on some models
Possible causes
- Faulty clutch pedal position sensor B or its internal track or switchlikely
- Damaged, chafed or corroded wiring or connector at the sensor (open circuit or high resistance in the ground or signal wire)likely
- Signal wire shorted to the reference supply or another voltage sourcepossible
- Sensor poorly adjusted, loose or displaced on the pedal box, giving an out of range readingpossible
- Poor sensor ground or supply fault from a wiring harness or connector problem elsewherepossible
- Fault within the control unit or an outdated calibration, where the manufacturer lists it as a known issuerare
How to diagnose
- Read all stored codes and freeze frame data, noting whether other clutch, brake or pedal sensor codes are present, then check for any manufacturer service bulletins for your model.
- Inspect the pedal box area, sensor, connector and harness for damage, moisture, corrosion, loose fitting or signs of rubbing.
- With a scan tool, watch the live clutch pedal position values for sensor B while pressing and releasing the pedal and check they change smoothly and stay within the specified range.
- Check the sensor mounting and adjustment against the manufacturer's procedure, as this varies by model.
- Unplug the sensor and check the reference supply, ground and signal circuit voltages against the wiring diagram.
- Test wiring for continuity, short to voltage and high resistance between the sensor and control unit, with the battery disconnected where required.
- Compare sensor A and B readings where fitted, as they should agree according to the manufacturer's data.
- If wiring and sensor test fine, check the control unit power and grounds and look for any approved software update before suspecting the unit.
How to fix
- Replace the clutch pedal position sensor B if it fails the live data or resistance checks, and adjust or calibrate it as the manufacturer requires.
- Repair or replace damaged wiring and clean or renew corroded connector terminals.
- Repair any short to voltage in the signal circuit and restore the proper reference and ground.
- Refit or readjust the sensor correctly on the pedal box, replacing worn mounting parts.
- Apply an approved software update only if the manufacturer lists an outdated calibration as a known cause, or replace the control unit as a last resort after confirming the fault.
Can I keep driving?
The car may be driveable, but starting problems, stalling or loss of cruise control and start/stop can occur, so get it fixed soon. If the engine will not start reliably or stalls in traffic, avoid driving it.
Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.