OBD-II fault code

P0C5F: Drive Motor B Position Sensor Circuit B Circuit

What it means

The position sensor channel B of drive motor B reports a circuit 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 B uses a position sensor to report rotor position for motor phase control. The module monitors channel B's electrical circuit and sets P0C5F when it detects a circuit fault that makes Drive Motor B's commutation feedback unreliable.

Common causes

Most likely first.

  1. Position sensor failed
  2. Wiring fault

Symptoms

  • EV/hybrid system warning light on
  • Reduced motor power or torque
  • Possible limp mode or vehicle shutdown

How to diagnose it

  1. Read freeze-frame data and related hybrid or EV codes to identify when the Drive Motor B channel B circuit fault occurred and whether other sensor or supply faults are present.
  2. Check live data for Drive Motor B position sensor channel B and compare its behavior with other available motor position data.
  3. With the vehicle powered down according to the manufacturer's safety procedure, inspect the channel B sensor connector and harness for damage, looseness, corrosion, or chafing.
  4. Check sensor power and ground and test continuity of the Drive Motor B channel B signal wiring using the manufacturer's procedure.
  5. If the wiring and connections pass, test Drive Motor B's position sensor channel B against the manufacturer's specification.

Common fixes

  • Reseat and secure the Drive Motor B position sensor connector.
  • Repair damaged or chafed channel B wiring and restore poor connections.
  • Clean or repair corroded connector terminals.
  • Replace the Drive Motor B position sensor if its channel B circuit fails the specified test.

Can I keep driving?

The fault can reduce motor torque or trigger limp mode or shutdown, so avoid longer trips or situations where loss of propulsion would be hazardous. If power is reduced or operation becomes abnormal, stop somewhere safe and arrange 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.

Codes for the same component