What it means
Drive motor B phase W current is above the expected range. The code identifies a high-current condition but does not establish its cause.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
The inverter switches high-voltage power to drive motor B, while the hybrid control system monitors current in its W phase. This code sets when phase W current is higher than expected, which can happen if motor B is stalled or its phase wiring or windings are shorted.
Common causes
Most likely first.
- Short between motor phases
- Rotor stalled - high stall current
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 scan live hybrid data for drive motor B phase W current and related phase readings to see when the excess current occurs.
- Check whether the vehicle reports reduced-power mode or a motor stall condition, and note whether the fault appears during acceleration or at a standstill.
- With the vehicle made safe according to its high-voltage procedures, inspect motor B and inverter connectors and harnesses for damage, corrosion, or signs of overheating.
- Have a qualified technician test motor B phase-to-phase and phase-to-ground isolation and winding condition against the manufacturer's specification.
- Compare phase W current-sensor and inverter data with the other drive motor B phases to distinguish a measurement fault from a genuine current imbalance.
Common fixes
- Repair damaged or loose drive motor B phase wiring or connector terminals.
- Repair or replace a motor B winding or cable with a confirmed short.
- Repair or replace a stalled or mechanically binding drive motor B after confirming the cause.
- Replace or repair the inverter current-sensing or switching circuitry if testing isolates the fault there.
Can I keep driving?
Avoid driving if power is reduced, the vehicle behaves abnormally, or a hybrid warning directs you to stop; a stalled motor or short can trigger limp mode or shut the vehicle down. Arrange prompt diagnosis, and do not handle high-voltage components.
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.