What it means
The position sensor channel B of drive motor A reports a circuit low fault. Phase commutation feedback impaired on this channel.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
Drive Motor A's position sensor channel B provides rotor-position feedback for motor commutation. P0C5C sets when the module detects that channel B's signal is lower than the expected range, which can happen with a signal short to ground or a sensor or connector fault.
Common causes
Most likely first.
- Signal wire shorted to ground
- Internal sensor short
- Connector pins corroded - high contact resistance
Symptoms
- EV/hybrid system warning light on
- Reduced motor power or torque
- Possible limp mode or vehicle shutdown
How to diagnose it
- Read freeze-frame data and related hybrid or EV codes to confirm the conditions when Drive Motor A channel B was detected low.
- Check live data for channel B and compare it with other available Drive Motor A position data to confirm the low reading.
- With the vehicle powered down according to the manufacturer's safety procedure, inspect the channel B signal wire and connector for ground contact, chafing, corrosion, or damaged pins.
- Test the channel B signal wire for an unintended short to ground and check its connector contacts using the manufacturer's procedure.
- If the harness and terminals are sound, test the sensor's channel B output and internal circuit against the manufacturer's specification.
Common fixes
- Repair chafed channel B signal wiring that is contacting ground.
- Clean or repair corroded or damaged channel B connector terminals.
- Restore a loose or poor connection at the Drive Motor A sensor.
- Replace the position sensor if its channel B circuit is internally shorted or fails the specified test.
Can I keep driving?
A low channel B signal can impair motor control and lead to reduced torque, limp mode, or shutdown. Avoid driving if propulsion is reduced or unpredictable; if the vehicle operates normally, limit driving to what is needed to reach a safe place for service.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.