P2A9CAlternative Fuel Tank Select Valve C Control 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
- P2A9C reports a control voltage at select valve C above the level the commanded state permits. The usual reasons are an interrupted coil or wire on a valve the module switches to ground, which leaves supply voltage on the line, or a foreign voltage fed in from a damaged neighbouring wire. Valve C then ignores commands. In a staged strategy like the one Cespira patented, where the controller moves between supplies as their pressures drop below set limits, the step involving vessel C is lost, so its content is either never tapped or cannot be shut out of the sequence. Range falls and the engine may switch to its other fuel sooner. No manufacturer publishes P2A9C. Compare coil resistance with valves A and B where they are identical.
- What you may notice
- Malfunction lamp on
- Third vessel never drawn, range reduced
- Earlier change to the other fuel
- Likely causes
- LikelyOpen coil or wire on ground-switched valve C
- PossibleForeign voltage from a damaged neighbouring wire
- RareCorroded terminals at valve C
- 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: €100 – €1,200
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.