P2A6DAlternative Fuel Rail Pressure Regulator Inlet Pressure Sensor Circuit Intermittent/Erratic
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P2A6D is the dropout code of the regulator inlet pressure sensor: the signal jumps or briefly vanishes, but not long enough for a steady low or high verdict. The regulator normally lives in the engine bay, next to the right-hand strut mount on GM's 2015 Impala bi-fuel, and Blackstone requires warm engine coolant to circulate through its SAN209 unit so that it does not ice up. Its connector therefore sees heat, vibration and condensation. Loose terminals, a harness chafed against coolant hoses or moisture inside the plug are the usual suspects. No manufacturer publishes P2A6D; CARB expects circuit faults of such inputs to be detected. Wiggle-test the harness while watching live data, and look for corrosion in the connector.
- What you may notice
- Check engine light on, sometimes clearing again
- Gas gauge flickers or jumps
- Sporadic switch from gas to petrol while driving
- Likely causes
- LikelyLoose or widened terminal in the sensor connector
- PossibleCondensation or corrosion in the plug near the coolant-heated regulator
- PossibleHarness rubbing on hoses or brackets with intermittent contact
- 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: €60 – €500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.