P0BEF code meaning
Drive Motor A Phase W Current Sensor Circuit Low
Powertrain system Generic code P0Bxx codes Check engine light
What P0BEF means
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.
P0BEF at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyWorkshop only
- Typical labor1 to 6 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P0BEF
- Malfunction indicator lamp and hybrid warning
- Reduced power or no assist from drive motor A
Common causes of P0BEF
- Most likelyFailed phase W current sensor inside the inverter
- PossibleSensor signal or supply pulled to ground on the sensor board
- Less likelyPoor contact at an internal or external inverter connector
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Drive motor a phase w current sensorWiring harnessHybrid control module
What each part of P0BEF means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| B | Area: hybrid propulsion. |
| EF | The exact fault in that area. |
What to do next
- Note P0BEF and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P0BEF
What does P0BEF mean?
P0BEF means "Drive Motor A Phase W Current Sensor Circuit Low". P0BEF indicates that the phase W current sensor of the motor A inverter delivers a signal below its valid range. It is a generic code, so it means the same on every make.
Is it safe to drive with P0BEF?
Drive gently and only to a workshop. With P0BEF the car can go into limp mode (reduced power) to protect itself.
Will P0BEF fail an emissions test?
Yes, it can. P0BEF is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P0BEF to fix?
Difficulty: workshop only. A typical repair takes 1 to 6 hours of work. This is a job for a workshop.
Will P0BEF clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.