P2A23Alternative Fuel Tank Shutoff Valve B Control Circuit Performance/Stuck Off
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- P2A23 is stored when valve B is switched on electrically, but the gas system does not react as if that cylinder had opened. Software can only judge this from pressure: after the command, the reading downstream of the tank should rise, and a tank B pressure sensor, where fitted, should fall while gas is being used. No manufacturer publishes P2A23 or its thresholds. Bus maker New Flyer devotes bulletin SMB-169 to a tank solenoid stuck closed and explains how such a cylinder is vented through the purge line before the valve is replaced. Likely reasons are a jammed armature, a closed hand valve on that tank or debris. P2A22, P2A24 and P2A25 cover the electrical faults of the same valve, P2A42 the plausibility of its pressure sensor.
- What you may notice
- Check engine light
- Tank B stays full while the others empty
- Reduced range on gas
- Likely causes
- PossibleArmature of valve B jammed closed, e.g. by debris
- PossibleManual valve on tank B left closed
- RareTank or line pressure sensor reporting the response wrongly
- 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: €80 – €1,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.