What it means
The current sensor for drive motor A phase W reports a circuit low 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 monitors the current flowing through the motor’s W phase with a dedicated current sensor. This code sets when the phase W sensor signal is abnormally low, so the control module cannot trust its measurement of that phase.
Common causes
Most likely first.
- Signal wire shorted to ground
- Internal sensor short
- 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
- Record freeze-frame data and check live drive motor A phase W current sensor values and related inverter codes to confirm the low-signal condition.
- With the high-voltage system made safe according to the manufacturer's procedure, inspect the phase W sensor connector and harness for corrosion, damaged insulation, loose terminals, or a signal wire shorted to ground.
- Check the phase W signal, supply, and ground circuits for shorts to ground, opens, and high-resistance connections using the manufacturer's wiring information.
- Compare phase W sensor readings with phases U and V under the same conditions to determine whether only the W circuit is affected.
- If the circuit checks pass, test the drive motor A phase W sensor according to the manufacturer's procedure for an internal short or failed output.
Common fixes
- Clean and secure corroded or loose phase W connector terminals.
- Repair a phase W signal wire shorted to ground or otherwise damaged.
- Repair a poor sensor supply or ground connection.
- Replace the drive motor A phase W current sensor if it remains low with a verified circuit.
Can I keep driving?
Avoid driving if torque is reduced, limp mode is active, or the vehicle signals possible shutdown; it may lose drive unexpectedly. Arrange diagnosis before using the vehicle for a trip where stopping would be unsafe.
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.