What it means
The current sensor for drive motor B phase W reports a circuit high fault. Phase current measurement is unreliable.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
The phase W current sensor in drive motor B measures W-phase current for the hybrid or EV control module. This code sets when the signal is above the module’s expected range, commonly due to a short to battery voltage, an open sensor or a poor connector connection.
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 inspect live phase W current or sensor readings for a signal stuck high or inconsistent with phases U and V.
- After following the manufacturer’s high-voltage shutdown procedure, inspect the phase W sensor connector and harness for corrosion, damage or contact with a power feed.
- Test the phase W signal wire for a short to B+ and check sensor power, ground and signal circuits against the manufacturer’s specification.
- Check terminal fit and circuit continuity through the phase W connector and harness, including for an open sensor circuit.
- If the wiring checks out, test the phase W sensor and control module input using the manufacturer’s procedure.
Common fixes
- Clean and secure corroded phase W connector terminals.
- Repair phase W signal wiring shorted to B+ or otherwise damaged.
- Repair an open connection at the phase W sensor or its harness.
- Replace the phase W current sensor if it is confirmed open or continues to report high with sound wiring.
- Repair or replace the control module only if its input is confirmed faulty.
Can I keep driving?
The fault can trigger reduced torque, limp mode or shutdown. Avoid driving if power delivery is limited or erratic, since unreliable current feedback can lead to loss of propulsion.
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.