P224FAlternative Fuel Tank Shutoff Valve A Control Circuit High
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- P224F reports a control circuit of tank shutoff valve A that reads too high, typically a wire touching battery voltage. In TransEco Energy's AFCM fault list the cause is given as shorted to power, the MIL is lit and the gas system keeps working under the failure mode strategy. That matters because a valve held open by an external voltage can no longer be closed by the control unit: Ford's 2003 bi-fuel CNG system relies on closing the tank valve when gas pressure falls below 517 kPa, and GM's bi-fuel Impala keeps its cut-off solenoids energized only while the engine turns. Ford's Boss 302S list carries P224F too, though mislabelled as Low. P224E is the low side; CARB requires both directions to be monitored.
- What you may notice
- Check engine light
- Tank valve may stay open after switching off
- Likely causes
- LikelyControl wire of the tank valve shorted to battery voltage
- PossibleOutput stage in the alternative fuel control module stuck on
- RareWiring mistake after a conversion or repair
- 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 – €900
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.