P2A6FAlternative Fuel Rail Pressure Regulator Inlet Pressure Too High
- 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
- P2A6F reports a regulator inlet pressure above the calibrated maximum. Only cylinder pressure is present upstream of the regulator, so a genuinely high value usually comes from the tank side, such as overfilling at a dispenser without temperature compensation or a cold-filled cylinder that later warms up strongly; a transducer reading high but still in range is the other option. GM notes for the Impala bi-fuel, whose cylinder is rated at 3,600 psi, that stations limit fill pressure by temperature so that a car moved somewhere warmer is not overpressurised. Blackstone's SAN209 regulator allows up to 4,500 psig at the inlet and carries a relief device on the outlet. No manufacturer documents P2A6F. Verify the reading against a gauge before suspecting the tank.
- What you may notice
- Check engine light on
- Gas mode blocked as a precaution
- Often appears right after refuelling
- Likely causes
- LikelyInlet pressure sensor reading too high within its range
- PossibleCylinder overfilled or strongly warmed after a cold fill
- RareSensor or calibration not matching the installed cylinder pressure rating
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Hard · Usually a job for a workshop.Typical cost: €0 – €700
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.