Frayed, chafed, or intermittently shorted wiring in the sensor 'B' circuit, often near connectors or where the harness flexes; Corroded or loose electrical connector pins at the motor position sensor or the controller harness; Internal failure of the position sensor 'B' element, such as a worn wiper contact or failing hall-effect device; Electromagnetic interference from nearby high-voltage cables or poor shielding causing signal noise; Poor ground connection for the motor controller or sensor return circuit, leading to erratic reference voltage; Mechanical wear in the motor or resolver assembly that causes the sensor air gap to fluctuate

DTC codes / P0Cxx · Hybrid propulsion / P0C5E

P0C5EDrive Motor A Position Sensor Circuit B Circuit Intermittent/Erratic

P0C5E indicates that the powertrain control module has detected an intermittent or erratic signal from the 'B' circuit of the position sensor that monitors Drive Motor A, which is the primary traction motor in many hybrid and electric vehicles. The computer sets this code when the sensor's feedback voltage momentarily drops out, spikes, or becomes noisy beyond acceptable limits, rather than failing completely.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyProfessional

AreaHybrid propulsion

Symptoms you may notice

Illumination of the check engine light or service vehicle soon message, often with no other symptoms besides the warning light
Intermittent loss of propulsion or a brief hesitation during acceleration, especially under load or over bumps
Reduced power output or a limp-home mode triggered by the motor controller
Unusual noises or vibration from the drive motor area if the sensor signal affects commutation
In some cases, the vehicle may refuse to start or shift into gear if the fault is present at key-on

Common causes, most likely first

Frayed, chafed, or intermittently shorted wiring in the sensor 'B' circuit, often near connectors or where the harness flexes
Corroded or loose electrical connector pins at the motor position sensor or the controller harness
Internal failure of the position sensor 'B' element, such as a worn wiper contact or failing hall-effect device
Electromagnetic interference from nearby high-voltage cables or poor shielding causing signal noise
Poor ground connection for the motor controller or sensor return circuit, leading to erratic reference voltage
Mechanical wear in the motor or resolver assembly that causes the sensor air gap to fluctuate

How to diagnose and fix it

Inspect the sensor 'B' circuit wiring and connectors for chafing, corrosion, or loose pins, and repair as needed
Perform a wiggle test on the harness while monitoring live sensor data to reproduce the intermittent fault
Check the sensor reference voltage and ground at the controller connector with a multimeter to rule out supply issues
Scope the sensor 'B' signal for dropouts, noise, or irregular waveform shape while rotating the motor by hand or during a road test
Verify the sensor air gap and mounting integrity if the sensor is accessible without major disassembly
Replace the position sensor or resolver assembly if the signal is erratic and wiring is confirmed good
Clear the code and perform a relearn or calibration procedure if required by the manufacturer after repair

Intermittent sensor faults that fool technicians

A common misdiagnosis is replacing the drive motor or controller when the actual fault is a chafed wire inside the harness loom that only shorts when the engine mounts flex under torque.
The code can be set by a poor ground at the motor case or controller chassis, which introduces noise into the sensor return circuit without any visible wiring damage.
Some vehicles log P0C5E after a low-voltage event or battery replacement because the controller sees a momentary erratic signal during power-up, and the code may be a false ghost that clears after a drive cycle.
Aftermarket high-voltage cable routing or added electrical accessories can induce interference that mimics a failing sensor, so always check for recent modifications before condemning parts.
The 'B' circuit often refers to a redundant or secondary sensor winding, so a failure may not cause a complete no-start but can cause intermittent limp mode that is hard to reproduce in the shop.

Can I keep driving with P0C5E?

You can usually drive the vehicle to a repair shop if the only symptom is the warning light, but avoid hard acceleration and towing until the fault is diagnosed. If the vehicle enters limp mode or loses power intermittently, stop driving and have it towed to prevent a sudden loss of propulsion.

Tools that help

Tools we recommend are in the Auto Veteran shop on Amazon. As an Amazon Associate we earn from qualifying purchases.

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