P0BEFDrive Motor A Phase W Current Sensor Circuit Low
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P0BEF indicates that the phase W current sensor of the motor A inverter delivers a signal below its valid range. GM's limits: below -700 A for 0.05 of 0.1 s (2016 tables) or 0.1 of 0.15 s (2019), Type A; below -800 A, Type A, on the 2011 Volt; below -700 A, Type B, on the 2012 two-mode trucks; below -440 A, Type B, two trips, in the BAS Plus (eAssist) table. These readings lie far outside real phase currents, so a sensor output stuck near ground, a failed sensor or a supply fault is the likely cause. In the eAssist system this fault puts current control into a mode that ignores the sensors, and it disables the U-V-W correlation check P0BFD, so motor A runs with reduced output.
- What you may notice
- Malfunction indicator lamp and hybrid warning
- Reduced power or no assist from drive motor A
- Likely causes
- LikelyFailed phase W current sensor inside the inverter
- PossibleSensor signal or supply pulled to ground on the sensor board
- RarePoor contact at an internal or external inverter connector
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Workshop only · Usually a job for a workshop.Typical cost: €150 – €4,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.