Detroit DD16 GHG14 (2014-16) Fault Code: SPN 520323 FMI 4 (ACM) High Side Digital Output Circuit Failed Low

DESCRIPTION:
High side digital output circuit failed low.

MONITORED PARAMETER:
DEF dosing unit voltage.

TYPICAL ENABLING CONDITIONS:
DEF dosing enabled.

MONITOR SEQUENCE:
None

EXECUTION FREQUENCY:
Continuous when enabling conditions met.

TYPICAL DURATION:
Five seconds

DASH LAMPS:
1. MIL
2. CEL

ENGINE REACTION:
Derate 25%

VERIFICATION:
Parked regen

PROBABLE CAUSES:
1. DEF Dosing unit connector.
2. Wiring between the DEF dosing unit and ECM.