P0BF1 code meaning
Drive Motor B Phase U Current Sensor Circuit
Powertrain system Generic code P0Bxx codes Check engine light
What P0BF1 means
On hybrids with two electric machines, the inverter of drive motor B carries its own set of phase current sensors, which the motor control processor uses for torque control and to protect the power switches. P0BF1 is the general circuit code for the phase U sensor of motor B, meant for an electrical fault that is not classified as offset, low or high. No manufacturer documents this exact code publicly: GM's tables for the 2011 Volt, the 2012 and 2013 two-mode trucks and the 2016 to 2019 models list only P0BF2, P0BF3 and P0BF4 for this sensor. CARB requires hybrid sensor circuits to be monitored. Without a valid phase U value, motor B is usually limited or switched off.
P0BF1 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 P0BF1
- Hybrid system warning and malfunction indicator lamp
- Reduced power or no contribution from drive motor B
- Engine runs more often because electric drive is limited
Common causes of P0BF1
- Most likelyFailed phase U current sensor in the motor B inverter
- PossibleSupply or signal fault on the inverter's sensor board
- Less likelySoftware fault in the motor B control processor
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 u current sensorWiring harnessHybrid control module
What each part of P0BF1 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. |
| F1 | The exact fault in that area. |
What to do next
- Note P0BF1 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 P0BF1
What does P0BF1 mean?
P0BF1 means "Drive Motor B Phase U Current Sensor Circuit". On hybrids with two electric machines, the inverter of drive motor B carries its own set of phase current sensors, which the motor control processor uses for torque control and to protect the power switches. It is a generic code, so it means the same on every make.
Is it safe to drive with P0BF1?
Drive gently and only to a workshop. With P0BF1 the car can go into limp mode (reduced power) to protect itself.
Will P0BF1 fail an emissions test?
Yes, it can. P0BF1 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 P0BF1 to fix?
Difficulty: workshop only. A typical repair takes 1 to 6 hours of work. This is a job for a workshop.
Will P0BF1 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.