Faulty clutch position sensor, with an internal fault or a signal stuck high; Damaged, chafed or corroded wiring, including a signal wire shorted to supply voltage; Open circuit in the sensor ground or signal return, which makes the signal read high; Corroded, loose or water-contaminated connector at the sensor or control unit; Sensor misaligned, incorrectly fitted or out of adjustment after clutch or gearbox work; Faulty transmission or engine control unit, or an outdated calibration where the manufacturer has a known fix.

P087D

Clutch 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
7D: FaultThe specific fault in that area

What it means

P087D means the control unit has seen the signal from clutch position sensor 'B' sit above its expected voltage range. The sensor fitted, and what 'B' refers to, depends on the vehicle and transmission type, such as a manual with a clutch pedal sensor, an automated manual or a dual-clutch gearbox. The fault is usually set by a short to voltage, an open circuit in the signal or ground wire, or a faulty sensor.

Symptoms

Warning light on, possibly with a transmission or gearbox warning
Engine will not start, or start-stop and hill-hold features are disabled
Harsh, delayed or failed gear changes on automated or dual-clutch gearboxes
Transmission stuck in one gear or in limp-home mode
Cruise control not working
Erratic or no response from clutch pedal switch functions

Possible causes

Faulty clutch position sensor, with an internal fault or a signal stuck highlikely
Damaged, chafed or corroded wiring, including a signal wire shorted to supply voltagelikely
Open circuit in the sensor ground or signal return, which makes the signal read highlikely
Corroded, loose or water-contaminated connector at the sensor or control unitpossible
Sensor misaligned, incorrectly fitted or out of adjustment after clutch or gearbox workpossible
Faulty transmission or engine control unit, or an outdated calibration where the manufacturer has a known fixrare

How to diagnose

Read all stored and pending codes and the freeze frame data, and note any other clutch, transmission or sensor supply codes
Check for relevant manufacturer service bulletins for your model and transmission type
Visually inspect the sensor, its wiring and connectors for damage, rubbing, water ingress, corrosion or bent pins
Check the sensor mounting and alignment, especially if the clutch or gearbox has been worked on recently
Watch live data for the clutch position while operating the clutch or actuator, and look for a reading stuck high or one that jumps
Using the wiring diagram for the vehicle, check the sensor reference supply, ground and signal voltages at the connector with the ignition on
Test the wiring for continuity and for shorts to voltage or ground between sensor and control unit
Test or substitute the sensor only after the wiring and supply checks are good, then check the control unit last

How to fix

Repair or replace damaged wiring and fix any short to voltage or open circuit
Clean, repair or replace corroded or damaged connectors and terminals
Replace the clutch position sensor if it fails the checks
Refit or readjust the sensor to the manufacturer's procedure, with any required learn or calibration afterwards
Update the control unit software or replace the unit only if a fault or outdated calibration is confirmed
Clear the code and road test to confirm it does not return

Can I keep driving?

Medium severity

The car may still drive, but gear changes, starting or clutch control can be affected, and limp-home mode is possible. Have it checked soon, and avoid driving if it will not shift properly or could stall in traffic.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.