Detroit DD16 GHG14 (2014-16) Fault Code: SPN 1077 FMI 15 (MCM) Internal or External Leakage of the High Pressure Fuel System

NOTE: The motor control module (MCM) monitors the rail pressure and when a leakage rate is greater than 100 1/h, the MCM sets the code. There is no fault reaction (limp home mode) associated to this code.

POSSIBLE CAUSES:
1. External fuel leakage between the high pressure pump and fuel injectors.
2. High pressure pump (pumping elements).
3. Fuel injector (amplifier or needle) leakage.
4. Pressure limiting valve (PLV) leakage (internal).

PROBABLE CAUSES:
1. If any other codes present, fix those first.
2. Clear code and road test. If it doesn’t come back, return vehicle to customer.
3. Check for internal and external high pressure fuel system leakage.
4. Fuel injector failure.
5. Check for leakage from the pressure limiting valve.
6. High pressure fuel pump failure.