What it means
The current sensor for drive motor A 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
Drive motor A’s inverter relies on a current sensor for the motor’s W phase to regulate and monitor phase current. This code sets when that sensor circuit reports an abnormally high signal, leaving the module unable to measure phase W current reliably.
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 drive motor A phase W current sensor readings with related codes to establish when the high signal appears.
- With the high-voltage system made safe according to the manufacturer's procedure, inspect the phase W sensor connector and harness for corrosion, loose pins, damage, or a signal wire shorted to B+.
- Use the manufacturer's wiring information to test the phase W signal, supply, and ground circuits for shorts to B+, opens, and poor terminal contact.
- Compare phase W readings against drive motor A phases U and V under similar conditions to check whether the high reading is isolated to W.
- If the wiring is intact, test the phase W current sensor using the manufacturer's procedure and replace it if its output is still high.
Common fixes
- Clean and secure corroded or loose phase W connector terminals.
- Repair a phase W signal wire shorted to B+ or damaged harness.
- Restore a poor sensor supply or ground connection.
- Replace the drive motor A phase W current sensor if the circuit is sound and its output remains high.
Can I keep driving?
Do not continue a trip if the vehicle has lost power, entered limp mode, or warns that shutdown may occur; drive may be interrupted. Avoid high-demand driving until the phase W sensing fault is repaired.
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.