P0C5C

What it means

P0C5C is a generic powertrain code meaning the control unit has detected a low signal voltage or low input on circuit B of the position sensor for drive motor A, found on hybrid and electric vehicles. The motor control unit compares the sensor signal against an expected range and sets the code when it stays below the lower limit. Without a valid rotor position, the motor cannot be controlled accurately, so the system may limit power or shut the drive down.

Symptoms

• Warning lights on, such as the hybrid or EV system fault light, malfunction indicator lamp or a general powertrain warning
• Reduced power or the car going into limp mode
• Rough, jerky or hesitant acceleration from the electric motor
• Vehicle will not enter Ready mode or fails to move off
• Sudden loss of drive while moving
• Unusual whine or vibration from the motor

Possible causes

• Damaged, chafed or corroded wiring on the position sensor circuit B, such as a short to ground or high resistancelikely
• Poor connection at the motor position sensor connector or the motor control unit connector (loose pins, water ingress, corrosion)likely
• Faulty drive motor position sensor (resolver or equivalent), with an internal fault or low output on circuit Bpossible
• Low or missing sensor supply or reference voltage caused by a wiring or control unit faultpossible
• Fault inside the motor control unit or inverter that misreads the sensor signalrare
• Mechanical damage or misalignment of the sensor or rotor position after motor or gearbox workrare

How to diagnose

1. Read all stored and pending codes and the freeze frame data, noting the conditions when it set and any related motor or inverter codes
2. Check for manufacturer service information or bulletins for this model, as sensor design and circuit layout vary between vehicles
3. Inspect the wiring and connectors between the motor position sensor and the motor control unit for chafing, heat damage, corrosion and moisture
4. Check the connector pins for tension, fit and contamination, and repair any fault found
5. Observe live position sensor data and compare circuit A and circuit B signals, checking they respond smoothly when the motor turns
6. Following the manufacturer's high-voltage safety procedure, measure the sensor supply voltage, signal voltage and circuit resistance, and test for shorts to ground
7. Check the sensor resistance or output against the manufacturer's specification
8. Clear the code after repair and road test to confirm it does not return

How to fix

• Repair or replace damaged wiring, correcting any short to ground or high resistance in the circuit
• Clean, reseat or replace corroded or loose connectors and fix any water ingress
• Replace the drive motor position sensor if it is out of specification, and carry out any learn or calibration procedure the manufacturer requires
• Repair the cause of a low supply or reference voltage fault
• Replace or repair the motor control unit or inverter only after the wiring and sensor have been proven good

Can I keep driving?

Nearby codes

• P0C5BGenericDrive Motor A Position Sensor Circuit B Range/Performance
• P0C5DGenericDrive Motor A Position Sensor Circuit B High