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P0C55

Drive Motor B Position Sensor Circuit A

Generic OBD-II

What it means

The drive motor B position sensor circuit A has a fault in its circuit that the module has flagged. This sensor reports rotor position to the motor control module, which needs it to time the motor's phases and deliver smooth electric drive.

Can I keep driving? Usually yes in the short term, but electric drive power may be reduced or cut, so get it read soon. Do not open high-voltage (orange) cables or covers yourself; leave that to a trained technician.

What this part does

The drive motor position sensor, often called a resolver, reports the rotor's exact angle and speed inside the electric drive motor. The motor control module needs this to time the current in each phase correctly, which gives smooth torque. Work on high-voltage parts is for trained people only. When it fails, you may notice reduced power, a rough start, or no drive.

Common symptoms

What you'll notice

Common causes

Most likely first

  1. Faulty drive motor B position sensor
  2. Loose or damaged wiring/connectors in the drive motor B position sensor circuit
  3. Corroded or dirty drive motor B position sensor connections
  4. Malfunctioning engine control module (ECM)
  5. Mechanical issue with the drive motor A itself

How to diagnose & fix

Work through it in order

  1. Check and clean the connections and wiring of the drive motor B position sensor circuit A.
  2. Replace or repair any damaged or faulty drive motor B position sensor circuit A components.
  3. Calibrate or reset the drive motor B position sensor circuit A using proper diagnostic tools.

Related codes

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