Obdaryn

P228DFuel Pressure Regulator A Exceeded Control Limits - Pressure Too High

  • Generic OBD-II code · Powertrain
  • Turns on the check-engine light
  • Matters for the ITP
  • Can trigger limp mode
How the car detects it
P228D is the opposite of P228C: measured rail pressure stays above the setpoint for too long although regulator A should be cutting delivery. GM's gasoline table 25OBDG03A flags it when the high-pressure pump supplies more than requested for 10 of 12.5 s, as Type A; its 2018 diesel table uses minus 13 MPa with the metering unit in closed loop (Type B), and table 24OBDG07 minus 3 MPa for 7 s. Causes range from a pump control valve that will not shut off, via a pressure sensor reading wrong, to calibration: GM bulletin 17-NA-069 cures P228D on 5.3 L and 6.2 L V8s by reprogramming, and PACCAR bulletin E114 links it, with P0094, to defective unit pumps on MX-13 truck engines. Expect harsh running or derated power.
What you may notice
  • Check engine light
  • Louder injection noise or rough idle
  • Reduced power in some cases
Likely causes
  • LikelyPump control or metering valve not reducing delivery
  • PossibleEngine control software needing an update
  • PossibleRail pressure sensor reading too high
  • RareDefective unit or high-pressure pump (truck engines)
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: €100 – €1,800

Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.