P228AFuel Pressure Regulator A - Forced Engine Shutdown
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P228A is a protective shutdown code: the engine computer has stopped the engine because rail pressure could not be held even with fuel pressure regulator A at full authority. In GM's 2018 diesel tables regulator 1 (A) is the fuel metering unit on the high-pressure pump; the fault is logged when actual pressure lags the setpoint by more than 40 MPa while the commanded pump flow is already at its maximum, in 640 of 800 samples taken every 12.5 ms (about 8 s), as a Type A code. GM bulletin 18-NA-103 lists P228A and P228B next to P0087 when gelled winter diesel starves the in-tank pump. P228B is the same reaction for regulator B, P228C the milder control-limit warning. Expect a stall or no restart until supply is restored.
- What you may notice
- Engine stalls while driving or shuts off shortly after starting
- Long cranking or no restart
- Check engine light on, often with P0087
- Whining in-tank fuel pump in cold weather
- Likely causes
- LikelyFuel supply starved (gelled or waxed diesel, clogged filter, failing in-tank pump)
- PossibleFuel metering unit on the high-pressure pump sticking or worn
- PossibleHigh-pressure pump no longer reaching the required delivery
- RareLeak in the high-pressure circuit or injector return
- 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 – €3,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.