P0BF1Drive Motor B Phase U Current Sensor Circuit
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- 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.
- What you may notice
- 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
- Likely causes
- LikelyFailed phase U current sensor in the motor B inverter
- PossibleSupply or signal fault on the inverter's sensor board
- RareSoftware fault in the motor B control processor
- 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.