P0BF9Drive Motor B Phase W 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
- P0BF9 is reserved for a general circuit fault of the phase W current sensor in the drive motor B inverter, outside the offset, low and high categories that have their own codes. No manufacturer documents this exact code publicly; GM's tables from the 2011 Volt through 2019, and Jeep's 2020 Renegade and Compass PHEV bulletins, refer only to the specific siblings, chiefly P0BFA. CARB requires hybrid sensor circuits to be monitored. If the controller cannot trust phase W of motor B, it can no longer close the three-phase current balance checked by P0BFE and therefore limits or disables that motor. The sensor sits inside the inverter, so repair usually means replacing the inverter assembly.
- What you may notice
- Hybrid system warning and malfunction indicator lamp
- Reduced power or no contribution from drive motor B
- Likely causes
- LikelyFailed phase W 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.