P2CBFPCV Heater B Control Circuit Low
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- P2CBF is set when the control line of PCV heater B sits at ground potential at a moment the module expects a voltage on it. On the usual low-side layout, with supply fed directly to the heater and the module providing the ground, a short to ground on that line turns heater B on permanently regardless of command. The ventilation stays protected against frost, but the element draws current continuously and may age faster. No manufacturer documents P2CBF publicly; the A-side code P053B is checked by GM's 2016 diesels at coolant below 90 °C with 20 of 40 failing samples, Type C without lamp. A pinched harness against the engine block or a damaged connector is the typical find.
- What you may notice
- Code stored, MIL depending on manufacturer
- Heater B constantly on, slightly higher electrical load
- Usually no driveability complaint
- Likely causes
- LikelyControl wire pinched or chafed to engine ground
- PossibleDamaged connector at heater B
- RareOutput stage in the engine module shorted internally
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €20 – €200
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.