P2A93Alternative Fuel Tank Select Valve A Control Circuit Low
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P2A93 is stored when the module measures a voltage on the control line of tank select valve A that falls short of the level expected for the commanded state. With a low-side driver this usually means the line touches ground, which can energise the solenoid permanently and keep valve A in its switched position regardless of the command. If the valve is fed from the positive side instead, the same fault overloads that output, which then usually switches itself off. In both cases the module can no longer choose the vessel, so the automatic change from an empty tank to a full one, as described in Westport's two-vessel patent, cannot be relied on. Valves near cryogenic lines collect condensation, so water in the connector is a plausible cause. No manufacturer documents P2A93; P2A94 is the high case.
- What you may notice
- Malfunction lamp on
- Tank selection stuck, one vessel emptied completely
- Fuse or output protection of the gas module trips
- Likely causes
- LikelyControl wire of valve A chafed through to ground
- PossibleCondensation or water in the connector of valve A
- RareShorted turns in the coil of valve A
- 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.