P2A29Alternative Fuel Tank Shutoff Valve C Control Circuit High
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- P2A29 sets when the drive circuit of shutoff valve C sits at a high level, as with a wire touching battery voltage or a driver stage inside the module that will not switch off. TransEco's table for its AFCM v1.4 gives a short to power as the cause, with the MIL on and gas operation maintained. Ford names P2A29 in its Boss 302S code list. GM's bi-fuel Impala powers the cut-off solenoid on its tank only while the engine cranks or runs; a valve that remains live afterwards defeats the purpose of the lock, which is to hold gas in the cylinder when the vehicle stands or the fuel supply has been cut. Wiring mistakes after a conversion deserve a look. P2A28 is the low-side code for valve C.
- What you may notice
- Check engine light
- Cylinder C not sealed when the engine is off
- Likely causes
- LikelyValve C control wire in contact with battery voltage
- PossibleDriver stage for valve C will not switch off
- RareValve C wired to a permanent feed after a conversion
- 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 – €1,200
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.