P00B9Low Pressure Fuel System Pressure - Too Low. Low Ambient Temperature
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- Needs a drive cycle to confirm a fix
- How the car detects it
- This code reports too low a pressure in the low-pressure fuel supply between the lift pump and the high-pressure pump under the additional condition of low ambient temperature. It separates cold-related supply problems from the general case. A typical mechanism, documented for diesel engines, is wax separating from insufficiently winterised fuel at sub-zero temperatures and clogging the filter or tank strainer. No manufacturer description naming this exact code, its thresholds or the vehicles using it was found.
- What you may notice
- Check engine light on
- Hard or no cold start
- Jerking or loss of power after starting
- Likely causes
- LikelyWax separation from summer or insufficiently winterised diesel in frost
- PossibleFuel filter clogged or water in the filter frozen
- PossibleFuel filter heater faulty
- RareLift pump weak
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Easy · Often possible to do yourself.Typical cost: €30 – €600
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.