Detroit DD15 GHG14 (2014-16) Fault Code: SPN 157 FMI 15 (MCM) Rail Pressure Level for Injection Enabling Not Reached

NOTE: The motor control module (MCM) monitors the rail pressure and when rail pressure deviation is greater than 200 bar, while under a load, the MCM sets the code.

POSSIBLE CAUSES:
1. External fuel leakage between the high pressure pump and fuel injectors.
2. Pressure limiting valve leakage (Internal).
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 (amplifier or needle) leakage.
8. Fuel contamination.
9. Rail pressure sensor.
10. Motor control module (MCM).

NOTE: The ECM monitors the rail pressure and when it changes more than 200 bar for 8 seconds the code is set.

PROBABLE CAUSES:
1. External fuel leakage between the high pressure pump and fuel injectors.
2. Pressure limiting valve leakage (internal).
3. Fuel filter integrity (loose caps, plugged filters).
4. Fuel supply issue (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 contaminated (oil, gas, etc…).
9. Rail pressure sensor or connector/harness.
10. Engine ECM failure.