Detroit DD15 GHG14 (2014-16) Fault Code: SPN 157 FMI 18 (MCM) Fuel Rail Pressure Too High

DESCRIPTION:
Fuel rail pressure too high.

MONITORED PARAMETER:
Fuel rail pressure

TYPICAL ENABLING CONDITIONS:
Closed loop and actual RP greater than 200 bar of desired RP.

MONITOR SEQUENCE:
None

EXECUTION FREQUENCY:
Continuous when enabling conditions met.

TYPICAL DURATION:
8 seconds

DASH LAMPS:
1. MIL
2. CEL

ENGINE REACTION:
Derate 25%

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

NOTE: The motor control module (MCM) monitors the fuel rail pressure, and when fuel rail pressure deviation is greater than 200 bar higher than requested fuel rail pressure for eight seconds, the MCM sets the code.

POSSIBLE CAUSES:
1. Faulty fuel rail pressure sensor.
2. Faulty quantity control valve (QCV).
3. Faulty MCM.
4. Faulty wiring.

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. Fuel rail pressure sensor connector/harness.
2. Fuel rail pressure sensor.
3. Failed Quantity Control Valve.
4. Failed ECM.