An open circuit or high-resistance connection in the sensor B signal wire, often at a connector or splice; A short to voltage on the signal circuit, which can occur where the harness rubs against a metal bracket; Failure of clutch position sensor B itself, typically an internal open circuit or worn potentiometer track; Corroded or backed-out terminals at the sensor connector or at the PCM harness connector; A poor ground connection shared by the sensor and other pedal-mounted components; Mechanical wear in the clutch pedal assembly that prevents sensor B from reaching its expected travel range; A faulty PCM driver circuit, which is rare but possible after water intrusion or a voltage spike

DTC codes / P08xx · Transmission / P087D

P087DClutch Position Sensor B Circuit High

Q: What does code P087D mean?

Clutch Position Sensor B Circuit High. P087D indicates that the powertrain control module (PCM) has detected an abnormally high voltage on the signal circuit for clutch position sensor B, which is typically a secondary or redundant clutch pedal position sensor used on manual or automated manual transmissions. The PCM expects the sensor's output to stay within a calibrated voltage range as the clutch pedal moves, and a sustained high reading tells the module that the circuit is open, shorted to voltage, or that the sensor has failed.

P087D indicates that the powertrain control module (PCM) has detected an abnormally high voltage on the signal circuit for clutch position sensor B, which is typically a secondary or redundant clutch pedal position sensor used on manual or automated manual transmissions. The PCM expects the sensor's output to stay within a calibrated voltage range as the clutch pedal moves, and a sustained high reading tells the module that the circuit is open, shorted to voltage, or that the sensor has failed.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaTransmission

Symptoms you may notice

Illumination of the check engine light or service transmission message with no other noticeable change in vehicle behavior
Difficulty starting the engine because the clutch pedal position is not recognized as depressed
Inconsistent or delayed engagement when releasing the clutch pedal, sometimes accompanied by a shudder
Cruise control or hill-start assist becoming unavailable because the PCM cannot confirm clutch pedal status
Rough or jerky gear changes on vehicles with an automated manual gearbox
A no-crank condition where the starter is inhibited despite the clutch pedal being fully pressed

Common causes, most likely first

An open circuit or high-resistance connection in the sensor B signal wire, often at a connector or splice
A short to voltage on the signal circuit, which can occur where the harness rubs against a metal bracket
Failure of clutch position sensor B itself, typically an internal open circuit or worn potentiometer track
Corroded or backed-out terminals at the sensor connector or at the PCM harness connector
A poor ground connection shared by the sensor and other pedal-mounted components
Mechanical wear in the clutch pedal assembly that prevents sensor B from reaching its expected travel range
A faulty PCM driver circuit, which is rare but possible after water intrusion or a voltage spike

How to diagnose and fix it

Connect a scan tool and read live data for clutch position sensor B while slowly pressing and releasing the clutch pedal to confirm the voltage stays high and does not follow pedal travel
Inspect the sensor B connector and the PCM connector for corrosion, loose terminals, or pushed-out pins, and repair as needed
Measure resistance and voltage drop on the sensor B signal wire from end to end while wiggling the harness to expose an intermittent open
Check for a short to voltage on the signal circuit by disconnecting both ends and measuring voltage to ground with the key on
Test the sensor B output with a multimeter or oscilloscope at the sensor pins to verify it changes smoothly through its range
If the circuit tests good, substitute a known-good sensor B and recheck live data before condemning the PCM
Clear the code and perform a road test that includes several complete clutch pedal cycles to confirm the repair

Clutch sensor B faults that fool good technicians

A high voltage reading on sensor B often comes from an open signal wire rather than a failed sensor, so resistance testing the harness before replacing parts saves time and money.
On many vehicles sensor B is a redundant safety signal that only the PCM monitors for plausibility, meaning the vehicle may drive normally and the only clue is the stored code.
A worn clutch pedal pivot or a missing pedal return bumper can hold sensor B at the top of its travel, producing a high voltage that looks exactly like an electrical fault.
Water intrusion into the under-dash connector area or a previous windshield replacement that leaked onto the pedal assembly is a commonly missed cause of this code.
Aftermarket floor mats or pedal covers that limit full clutch pedal travel can prevent sensor B from reaching its low-voltage end, setting a high-voltage code without any component failure.

Can I keep driving with P087D?

The vehicle is usually safe to drive because sensor B is typically a redundant input, but you should avoid relying on cruise control or hill-start assist and be prepared for a possible no-crank condition. Have the circuit inspected promptly, especially if the engine has ever failed to start because the clutch pedal was not recognized.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.