Damaged, chafed or corroded wiring or connectors in the motor position sensor circuit, including open circuit, short circuit or high resistance; Faulty drive motor position sensor (resolver or encoder type depends on the model); Water ingress or contamination at the motor or sensor connector; Sensor mounting or rotor target misaligned or damaged after repair work or mechanical damage; Fault in the motor control unit or inverter that processes the position signal; Outdated control unit software where the manufacturer has issued a known fix for this code.

P0C5F

Drive Motor B Position Sensor Circuit B.

Generic
Powertrain
Generic code
High severity

How this code is built

P: SystemPowertrain
0: Defined bySAE, the same on every car
C: AreaHybrid propulsion
5F: FaultThe specific fault in that area

What it means

P0C5F is the generic code for a fault in the Drive Motor 'B' Position Sensor, Circuit 'B'. It is found on hybrid and electric vehicles. The motor control unit relies on this sensor to know the rotor angle, so it can time the motor's phase currents correctly. The code sets when the signal is missing, out of range, implausible or disagrees with other data. Which sensor type, which motor is 'B' and which channel is 'Circuit B' depends on the make and model.

Symptoms

Warning lights on the dashboard, such as the hybrid or EV system fault light or the general malfunction light
Reduced power or limp-home mode
Loss of drive or the car refusing to move or enter Ready mode
Rough, jerky or noisy motor operation, or a whine from the drive unit
Engine starting more often or running longer on a hybrid, because motor B is not being used
Intermittent faults that vary with temperature or vibration

Possible causes

Damaged, chafed or corroded wiring or connectors in the motor position sensor circuit, including open circuit, short circuit or high resistancelikely
Faulty drive motor position sensor (resolver or encoder type depends on the model)likely
Water ingress or contamination at the motor or sensor connectorpossible
Sensor mounting or rotor target misaligned or damaged after repair work or mechanical damagepossible
Fault in the motor control unit or inverter that processes the position signalrare
Outdated control unit software where the manufacturer has issued a known fix for this coderare

How to diagnose

Read all stored and pending codes with freeze frame data, and note whether other drive motor, inverter or resolver codes are present and under what conditions the fault set
Check for manufacturer service bulletins and software updates relevant to this model and code
Visually inspect the sensor wiring, connectors and any shielding between the motor and the control unit for chafing, corrosion, water, bent pins or loose fit. Only a trained technician should work near high-voltage components, and the high-voltage system must be made safe first following the manufacturer procedure
Wiggle-test the harness with live data on the sensor signal to look for dropouts or intermittent faults
With the system made safe, test the circuit for continuity, short to earth, short to supply and resistance against the manufacturer specification
Test the sensor itself against the manufacturer specification, such as coil resistance for a resolver, and check its mounting and air gap or alignment where applicable
Check the live position and speed data for plausibility against the other motor and vehicle speed
If wiring and sensor are good, check the control unit supply and earths before suspecting the control unit

How to fix

Repair or replace damaged wiring, terminals or connectors, and seal against moisture
Replace the faulty drive motor position sensor or the motor assembly if the sensor is not serviced separately, then carry out any required alignment or learning procedure
Dry out and clean contaminated connectors and find and fix the source of water ingress
Correct the sensor mounting or alignment and repair any mechanical damage to the rotor target
Update the control unit software only if the manufacturer lists this as a fix for the fault, or repair or replace the inverter or motor control unit if it is confirmed faulty

Can I keep driving?

High severity

Avoid driving if the car is in limp mode or the drive system warning is showing, as power can drop or be lost without warning. Have it inspected by a technician trained in hybrid and electric systems before further use.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.