P0C5B

What it means

P0C5B is the generic code for the position sensor (resolver or encoder) of drive motor A, where the signal on circuit B is out of range or does not behave as expected. The motor control unit uses this signal to know the rotor angle so it can time the current to the motor windings. It set the code because the signal was implausible, for example the wrong amplitude, noise, or disagreement with the other circuit or the expected motor behaviour. Which wires or signals count as circuit B depends on the model.

Symptoms

• Hybrid or electric system warning light on
• Reduced power or limp-home mode
• Jerky, rough or hesitant drive-away
• Engine starting more often than normal or electric-only drive unavailable on a hybrid
• Vehicle will not enter ready mode or loses drive while moving
• Other drive motor or inverter fault codes stored alongside

Possible causes

• Damaged wiring, poor connector contact or corrosion in the motor position sensor circuitlikely
• Electrical interference or poor shielding or earthing on the sensor signal wirespossible
• Faulty drive motor position sensor (resolver or encoder)possible
• Sensor mounted out of position or loose, or mechanical damage to the sensor or rotor targetpossible
• Fault in the inverter or motor control unit's sensor interfacerare
• Outdated or faulty control unit software where the manufacturer lists it as a known causerare

How to diagnose

1. Read all stored and pending codes and the freeze frame data, noting speed, motor speed, temperature and ready state when the fault set
2. Check for manufacturer bulletins or known issues for this model and motor, as circuit B and the sensor design vary
3. Follow the manufacturer's high-voltage safety procedure before touching any orange cabling or components, and only let trained technicians work on the high-voltage system
4. Visually inspect the sensor wiring and connectors at the motor and inverter for chafing, water ingress, bent pins, corrosion and loose locking tabs
5. Check the live data for motor speed and rotor angle for erratic or implausible readings, comparing with other motor speed signals if available
6. Test the sensor circuit for continuity, shorts and resistance against manufacturer specifications, and check the shielding and earth connections
7. Measure the sensor coil resistance or signal quality to specification, and check the sensor mounting and condition
8. If wiring and sensor test good, check for software updates and have the inverter or control unit assessed

How to fix

• Repair or replace damaged wiring and clean or replace faulty connectors in the sensor circuit
• Restore damaged shielding or earth connections that are causing interference
• Replace the drive motor position sensor, or the motor assembly if the sensor is not serviceable separately, and set up as the manufacturer requires
• Correct the sensor mounting or repair mechanical damage affecting the sensor or rotor target
• Update the control unit software if an outdated version is a known cause, or repair or replace the inverter or control unit if it is proven faulty

Can I keep driving?

Nearby codes

• P0C5AGenericDrive Motor A Position Sensor Circuit B
• P0C5CGenericDrive Motor A Position Sensor Circuit B Low