What it means
The control module detected a fault associated with drive motor B phase V current. The code alone does not identify whether the cause is in the current measurement circuit, inverter, or motor.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
Drive motor B phase V is one of the three current paths the inverter uses to produce torque. The module monitors phase V current and sets this code when it detects an associated fault, but the code alone does not show whether the cause is in the sensor, wiring, inverter, or motor.
Common causes
Most likely first.
- Phase current sensor failed
- Wiring fault
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 compare live motor B phase V current with phases U and W, noting the conditions present when the code set.
- Check for companion motor B, inverter, or current-sensor codes that could help locate the fault.
- With the vehicle safely powered down according to the manufacturer’s procedure, inspect motor B phase V wiring and connectors for corrosion, loose pins, heat damage, or chafing.
- Test the phase V current-sensor supply, ground, and signal circuit for continuity and shorts using the manufacturer’s wiring information.
- If the wiring passes, test the phase V current sensor against the manufacturer’s specification, then assess the inverter or motor if the sensor is sound.
Common fixes
- Clean and secure a loose or corroded motor B phase V connector.
- Repair damaged phase V wiring or its sensor signal circuit.
- Replace the phase V current sensor if testing confirms a failed output.
- Repair the inverter or motor only if testing isolates the fault to that component.
Can I keep driving?
Limit driving if motor power is reduced, and stop safely if limp mode or a shutdown warning appears because the vehicle may lose propulsion. Arrange prompt diagnosis of the phase V current fault.
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.