OBD-II code · Powertrain (generic, extended)
P2A9D Alternative Fuel High Pressure System Small Leak
The AFCM detects a small leak in the high-pressure alternative fuel system based on pressure decay rate after engine shutdown. Common in CNG vehicles where seal aging causes slow gas loss.
Is it safe to drive with P2A9D?
Usually safe for short trips, but don’t ignore it: the underlying fault can get more expensive over time.
Common causes
- Most likelySeal aged at fitting or valve
- PossibleHigh-pressure fitting loose
Repair at a glance
- Difficulty
- Hard
- DIY friendly
- Best left to a mechanic
- Typical labour
- 1–6 h
- Emissions test
- Likely to fail
- After the fix
- A drive cycle is needed before the light stays off
- Parts involved
- Alt Fuel High Pressure Lines, Alt Fuel Seals, Alt Fuel Tank
Related codes
- P2A9AAlternative Fuel Tank Select Valve C Control Circuit Performance
- P2A9BAlternative Fuel Tank Select Valve C Control Circuit Low
- P2A9CAlternative Fuel Tank Select Valve C Control Circuit High
- P2A9EAlternative Fuel Return Line Valve Control Circuit/Open
- P2A9FAlternative Fuel Return Line Valve Control Circuit Range/Performance
- P2AA0Alternative Fuel Return Line Valve Control Circuit Low
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.