Detroit DD16 GHG14 (2014-16) Fault Code: SPN 4374 FMI 1 (ACM) Over Pressurized DEF System

Description

DESCRIPTION:
Over Pressurized Diesel Exhaust Fluid (DEF) System.

MONITORED PARAMETER:
DEF Pump Speed vs. DEF Pressure.

TYPICAL ENABLING CONDITIONS:
1. DEF pump enabled.
2. On-Off-Cycle request.

MONITOR SEQUENCE:
None

EXECUTION FREQUENCY:
Continuous when enabling conditions met.

TYPICAL DURATION:
2 minutes

DASH LAMPS:
1. MIL
2. CEL

ENGINE REACTION:
None

VERIFICATION:
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. Doser unit failure.
4. DEF return line failure.
5. DEF tank header failure.