P2A6CAlternative Fuel Rail Pressure Regulator Inlet Pressure Sensor Circuit High
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P2A6C means the regulator inlet pressure signal sits above its plausible voltage ceiling. Typical causes are a signal wire touching a 5 V or battery-voltage circuit, an open sensor ground, an open signal line that the module pulls up internally (depending on its design), or an internal transducer fault. Unlike a genuinely excessive cylinder pressure, which P2A6F covers, the value here lies outside anything the sensor can physically deliver. On GM's Impala bi-fuel the regulator-mounted sensor covers a cylinder range of 3,600 psi; ITT's patented regulator places one transducer at the inlet port and a second at the outlet. No manufacturer documents P2A6C with thresholds. A broken ground often pins the reading at maximum, so check ground and connector first.
- What you may notice
- Check engine light on
- Gas gauge stuck at full regardless of consumption
- Gas mode blocked, bi-fuel vehicle switches to petrol
- Likely causes
- LikelySensor ground open or connector terminal pushed out
- PossibleSignal wire shorted to 5 V reference or battery voltage
- PossibleInlet pressure transducer internally faulty
- 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: €80 – €600
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.