P2CFBBelt Integrated Starter Generator Belt Tensioner Control Circuit High
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- P2CFB mirrors P2CFA on the high side: the tensioner control circuit of a belt integrated starter generator shows a voltage above the expected range, usually from a wire touching a battery-voltage feed or a driver stage that cannot switch off. The actuator may then be held in one position permanently. Ford's patent US 12,577,903 explains why that matters: an active tensioner is switched to high tension for the start phase, when the BISG transmits the greatest torque, and the control unit watches for belt slip during cranking. A tensioner stuck at the wrong tension risks slip at start or extra belt and bearing wear in normal driving. No manufacturer publicly documents P2CFB; patents and the CARB circuit-monitoring rules are the basis here. P2CF9 covers an open circuit, P2CFA a low signal.
- What you may notice
- Belt slip or squeal at engine start
- Faster belt wear or bearing noise
- MIL on, stop-start or assist unavailable
- Likely causes
- LikelyControl wire shorted to a supply voltage
- PossibleOutput stage in the module unable to switch off
- RareActuator electronics reporting an implausibly high level
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €50 – €700
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.