P0BFBDrive Motor B 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
- P0BFB indicates that the phase W current sensor of the motor B inverter delivers a signal below its valid range. GM's limits: below -800 A on the 2011 Volt (Type A, 4 of 6 samples at 10.4 ms), below -700 A on the 2012 and 2013 two-mode trucks (Type B, two trips) and below -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). The threshold lies well outside any phase current motor B can carry, so the likely cause is a sensor output stuck near ground, a failed sensor or a supply fault on the sensor board. P0BFA covers a shifted zero, P0BFC the high side. While the code is active, motor B delivers reduced or no torque.
- What you may notice
- Malfunction indicator lamp and hybrid warning
- Reduced power or no contribution from drive motor B
- Likely causes
- LikelyFailed phase W current sensor in the motor B 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.