P0BF8 code meaning
Drive Motor B Phase V Current Sensor Circuit High
Powertrain system Generic code P0Bxx codes Check engine light
What P0BF8 means
P0BF8 sets when the phase V current sensor of drive motor B reports more current than its valid range allows. GM uses above 800 A on the 2011 Volt with the PWM output disabled (Type A), above 700 A on the 2012 and 2013 two-mode trucks (Type B, two trips) and above 700 A for 0.05 of 0.1 s in the 2016 tables or 0.1 of 0.15 s in a 2019 table (Type A, one trip). Such a reading while the inverter is not switching, or far above the overcurrent limit, isolates a sensor-side fault such as a signal shorted to the supply or a broken reference ground. It pairs with P0BF7 for the low side and P0BF6 for offset; real overcurrent appears as P0C04. Expect motor B to be derated and further inverter codes in memory.
P0BF8 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 P0BF8
- Malfunction indicator lamp and hybrid warning
- Reduced power from drive motor B
Common causes of P0BF8
- Most likelyFailed phase V current sensor in the motor B inverter
- PossibleSensor signal shorted to the sensor supply voltage or open reference ground
- 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 b phase v current sensorWiring harnessHybrid control module
What each part of P0BF8 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. |
| F8 | The exact fault in that area. |
What to do next
- Note P0BF8 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 P0BF8
What does P0BF8 mean?
P0BF8 means "Drive Motor B Phase V Current Sensor Circuit High". P0BF8 sets when the phase V current sensor of drive motor B reports more current than its valid range allows. It is a generic code, so it means the same on every make.
Is it safe to drive with P0BF8?
Drive gently and only to a workshop. With P0BF8 the car can go into limp mode (reduced power) to protect itself.
Will P0BF8 fail an emissions test?
Yes, it can. P0BF8 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 P0BF8 to fix?
Difficulty: workshop only. A typical repair takes 1 to 6 hours of work. This is a job for a workshop.
Will P0BF8 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.