P2A23 code meaning
Alternative Fuel Tank Shutoff Valve B Control Circuit Performance/Stuck Off
Powertrain system Generic code P2Axx codes Check engine light
What P2A23 means
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.
P2A23 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyHard
- Typical labor0.5 to 4 hours
- Clears after repairAfter a drive cycle
Symptoms of P2A23
- Check engine light
- Tank B stays full while the others empty
- Reduced range on gas
Common causes of P2A23
- PossibleArmature of valve B jammed closed, e.g. by debris
- PossibleManual valve on tank B left closed
- Less likelyTank or line pressure sensor reporting the response wrongly
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Alt fuel tank shutoff valve bWiring harnessAfcm
What each part of P2A23 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| A | Area: hybrid propulsion. |
| 23 | The exact fault in that area. |
What to do next
- Note P2A23 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P2A23
What does P2A23 mean?
P2A23 means "Alternative Fuel Tank Shutoff Valve B Control Circuit Performance/Stuck Off". P2A23 is stored when valve B is switched on electrically, but the gas system does not react as if that cylinder had opened. It is a generic code, so it means the same on every make.
Is it safe to drive with P2A23?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P2A23 fail an emissions test?
Yes, it can. P2A23 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P2A23 to fix?
Difficulty: hard. A typical repair takes 0.5 to 4 hours of work. This is a job for a workshop.
Will P2A23 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.