Detroit DD15 GHG14 (2014-16) Fault Code: SPN 4374 FMI 0 (ACM) Under Pressurized Diesel Exhaust Fluid System

DESCRIPTION:
This code sets when the Diesel Exhaust Fluid (DEF) pump speed is higher than normal for a given DEF pressure.

MONITORED PARAMETER:
1. DEF Pump Speed.
2. DEF Pressure.

MONITOR SEQUENCE:
None

EXECUTION FREQUENCY:
Continuous when enabling conditions met.

TYPICAL DURATION:
Continuous until resolved.

DASH LAMPS:
1. MIL
2. CEL

ENGINE REACTION:
Derate 25%

VERIFICATION:
SCR ADS Self-Check.

NOTE: If any other codes are present, repair them first.

PROBABLE CAUSES:
1. Check connectors & wiring for: DEF dosing unit, DEF pump, Aftertreament Control Module, Chassis/ATS harness wiring/connector.
2. Contaminated DEF tank (Fuel, water, etc…).
3. Check DEF lines for blockages, kinks, cracks, etc…
4. DEF doser unit inlet screen.
5. DEF suction filter.
6. Pressure relief valve.
7. DEF tank header.