Wiring fault in the position sensor circuit, such as a short to ground or chafed insulation; Corroded, loose or damaged connector at the motor or the inverter/motor control unit; Faulty drive motor B position sensor (resolver) or its internal winding; Moisture or coolant/oil contamination in the motor sensor connector or housing; Fault inside the inverter or motor control unit's sensor interface; Low or unstable 12V supply affecting the sensor excitation or control unit.

P0C61

Drive Motor B Position Sensor Circuit B Low.

Generic
Powertrain
Generic code
High severity

How this code is built

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

What it means

P0C61 is a generic hybrid or electric vehicle code for the position sensor circuit of drive motor B, circuit B, reading low. The motor control unit monitors the rotor position sensor (usually a resolver) to time the motor currents accurately. It saw the signal voltage below the expected range, so it can no longer trust the rotor position. Which circuit is 'B' and how the sensor is wired depends on the model and drivetrain layout.

Symptoms

Hybrid or EV system warning light, or a ready-system fault message
Reduced power or the car going into a limp-home mode
Drive motor B not assisting, or the car running on the engine or other motor only
Rough, jerky or hesitant acceleration
Car will not enter ready mode or will not move
Possible shudder or noise from the motor at low speed

Possible causes

Wiring fault in the position sensor circuit, such as a short to ground or chafed insulationlikely
Corroded, loose or damaged connector at the motor or the inverter/motor control unitlikely
Faulty drive motor B position sensor (resolver) or its internal windingpossible
Moisture or coolant/oil contamination in the motor sensor connector or housingpossible
Fault inside the inverter or motor control unit's sensor interfacepossible
Low or unstable 12V supply affecting the sensor excitation or control unitrare

How to diagnose

Read all stored and pending codes with freeze frame data, noting vehicle speed, motor speed and conditions when the code set; check for related drive motor or inverter codes
Check the 12V battery condition and charging, as low voltage can cause false sensor faults
Follow the manufacturer's high voltage safety procedure; only trained technicians should work on or near high voltage components
Visually inspect the sensor harness and connectors at the motor and inverter for chafing, corrosion, moisture, bent pins or poor locking
Check live data for the motor B rotor position and speed values, and see whether they are fixed, missing or erratic
With the system safely isolated, test the sensor circuit for continuity, short to ground and winding resistance against the model's specification
Wiggle-test the harness with live data or a resistance meter connected to find intermittent faults
Check the control unit's sensor supply and signal, and look for software updates or service bulletins for your model

How to fix

Repair or replace damaged wiring in the position sensor circuit
Clean, dry or replace corroded or damaged connectors and terminals, and fix any water ingress
Replace the drive motor B position sensor or motor assembly, as the design allows
Replace or repair the inverter or motor control unit if the interface is confirmed faulty
Restore the 12V supply by repairing or replacing the battery or charging fault
Clear the code after repair and road test to confirm it does not return

Can I keep driving?

High severity

Avoid driving if the car is in limp mode, has lost drive or is behaving erratically, as power loss could be sudden. If it still drives normally, keep journeys to a minimum and have it diagnosed promptly by a hybrid or EV-trained technician.

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