Detroit DD13 GHG14 (2014-16) Fault Code: SPN 4331 FMI 16 (ACM) DEF Dosing Quantity High

NOTE: The fault indicates that the DEF pump speed is low compared to DEF quantity delivered. The CEL lamp will remain on until the fault is resolved.

NOTE: If code 3364-xx present, fix that first.

PROBABLE CAUSES:
1. Check all DEF supply lines for damage or leaks.
2. DEF tank is contaminated with gas, diesel, water, etc…
3. Doser valve failure.
4. DEF pump.
5. DEF pump connection/harness.