P0C5D

What it means

P0C5D means the hybrid or electric vehicle control unit has detected a high signal in circuit B of the position sensor for drive motor A. This sensor, usually a resolver or encoder, tells the inverter the rotor angle so it can time the motor current accurately. The control unit saw the circuit B signal voltage above its expected range, so the motor position can no longer be trusted. Which signal 'circuit B' refers to (for example one sensor channel or winding) depends on the model.

Symptoms

• Hybrid or EV system warning light on the dashboard, with the malfunction indicator lamp possibly on too
• Reduced power or limp-home mode
• Vehicle will not enter Ready mode or will not move
• Rough running, shuddering or jerking under acceleration
• Engine starting more often or running continuously on a hybrid as the motor is limited
• Other drive motor or inverter fault codes stored alongside

Possible causes

• Damaged, chafed or shorted wiring in the motor position sensor circuit B, including a short to a voltage supplylikely
• Poor connection, corrosion, moisture or bent or pushed-out pins at the position sensor connector or inverter connectorlikely
• Faulty drive motor position sensor (resolver or encoder)possible
• Fault in the inverter or motor control module's sensor interface circuitpossible
• Electrical interference or a damaged shield on the sensor wiringrare
• Mechanical damage or misalignment of the sensor on the motor, affecting its signalrare

How to diagnose

1. Read all stored codes and freeze frame data, noting any other drive motor, inverter or communication faults and the conditions when the code set.
2. Check for the manufacturer's technical bulletins and software updates relevant to the model and fault.
3. Visually inspect the position sensor wiring and connectors for chafing, heat damage, water ingress, corrosion and loose or bent pins. Only the high-voltage-trained should work near orange high-voltage cabling.
4. Follow the manufacturer's procedure to make the high-voltage system safe before any work on motor or inverter connectors.
5. Check the circuit B wiring for continuity, short to voltage and short to earth between the sensor and control unit, using the wiring diagram for the specific model.
6. Check the sensor's resistance or signal against the manufacturer's specification, since values vary by model and sensor type.
7. Monitor live sensor data while the fault is present and wiggle-test the harness to see if the signal changes.
8. If wiring and sensor test good, check the control unit's power, earths and sensor interface as directed by the manufacturer's procedure.

How to fix

• Repair or replace damaged wiring in the sensor circuit, using proper sealed repairs.
• Clean, re-seat or replace corroded or damaged connectors and terminals, and fix any source of water ingress.
• Replace the drive motor position sensor if it fails testing, and set it up as the manufacturer specifies.
• Repair or replace the inverter or motor control unit if the fault is confirmed to be inside it.
• Apply any manufacturer software update if an outdated calibration is a known cause for this fault, then clear the code and road test to confirm it does not return.

Can I keep driving?

Nearby codes

• P0C5CGenericDrive Motor A Position Sensor Circuit B Low
• P0C5EGenericDrive Motor A Position Sensor Circuit B Intermittent/Erratic