What it means
The position sensor channel A of drive motor B reports a circuit high 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's position sensor uses circuit A to send rotor-position feedback to the hybrid or EV control module. This code sets when the channel's signal rises above the calibrated threshold, which can result from a short to battery voltage, an open sensor, or a poor connector.
Common causes
Most likely first.
- Signal wire shorted to B+
- Open sensor
- 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
- Save freeze-frame data and check for related Drive Motor B position-sensor codes to identify whether the high reading is persistent or intermittent.
- With the vehicle powered down under the manufacturer's safety procedure, inspect circuit A's wiring and connector for damaged insulation, loose pins, corrosion, or contact with a power feed.
- Measure the circuit A signal and sensor supply using the wiring diagram and manufacturer's specification.
- Test the signal wire for a short to battery voltage and check the connector and harness for an open circuit or high-resistance contact.
- If the wiring and connector pass, test Drive Motor B's position sensor for an open or internal fault using the manufacturer's procedure.
Common fixes
- Repair circuit A wiring that is shorted to battery voltage.
- Restore an open connection or replace damaged terminals in Drive Motor B's sensor connector.
- Repair chafed wiring and secure the harness away from power conductors.
- Replace Drive Motor B's position sensor if testing confirms it is open or faulty.
Can I keep driving?
Avoid driving if power is reduced or the vehicle enters limp mode, and stop safely if shutdown is possible. A high position signal can interfere with motor control and may cause loss of drive.
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.