Detroit DD16 GHG14 (2014-16) Fault Code: SPN 520268 FMI 18 (MCM) Fuel Rail Pressure Too High, Similar Condition

DESCRIPTION:
Fuel rail pressure high.

MONITORED PARAMETER:
Fuel rail pressure.

TYPICAL ENABLING CONDITIONS:
Closed loop and actual rail psi greater than 200 bar (2900 psi) of desired rail psi.

MONITOR SEQUENCE:
None

EXECUTION FREQUENCY:
Continuous when enabling conditions met.

TYPICAL DURATION:
Eight seconds

DASH LAMPS:
MIL

ENGINE REACTION:
None

VERIFICATION:
Steady engine rpm 1400 – 1500: Two minutes.

NOTE: When rail pressure deviation is greater than 200 bar while under a load this code is set.

PROBABLE CAUSES:
1. External fuel leakage between the high pressure pump and fuel injectors.
2. Pressure limiting valve (PLV) leakage internally.
3. Fuel filter integrity (Loose caps, plugged filters).
4. Fuel supply issues (fuel level, fuel aeration, leaking fuel lines, fuel restrictions).
5. Intermittent loss of engine speed signal.
6. HIgh pressure pump internal failure.
7. Fuel injector leakage.
8. Fuel contamination.
9. Rail pressure sensor.
10. Failed MCM (Engine ECM).