P2A9AAlternative Fuel Tank Select Valve C Control Circuit Performance
- 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
- With P2A9A, select valve C passes its electrical tests, but the effect of switching does not show up as expected. The likely evidence is pressure: once vessel C is selected, its own tank pressure sensor should begin to fall with consumption and the pressure ahead of the regulator should match that vessel's level. If tank C stays untouched, or the pressure jumps to a value that fits another vessel, the valve has not moved or leaks internally. Cespira's patent shows why the selection matters, since its controller decides which supply goes to compression and which to the regulator from measured supply pressures. A partial fault may only appear in the cold. No manufacturer publishes P2A9A or the comparison it uses; P2A46 and P2A47 cover the tank C pressure sensor.
- What you may notice
- Malfunction lamp on
- Tank C level hardly changes over a tank cycle
- Fault appears mainly in cold weather
- Likely causes
- LikelyValve C not shifting fully because of wear or contamination
- PossibleInternal leakage letting vessel C feed in the wrong position
- RareFaulty tank C pressure reading misleading the check
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Workshop only · Usually a job for a workshop.Typical cost: €200 – €1,800
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.