Detroit DD15 GHG14 (2014-16) Fault Code: SPN 3242 FMI 20 (ACM) Diesel Oxidation Catalyst Temperature Drift – Inlet High or Outlet Low

DESCRIPTION:
70°C (126°F) difference during non-regeneration mode.

MONITORED PARAMETER:
Diesel oxidation catalyst (DOC) inlet temperature vs. DOC outlet temperature.

TYPICAL ENABLING CONDITIONS:
1. Coolant temperature greater than 60°C (140°F).
2. Regen not active in the last five minutes.

EXECUTION FREQUENCY:
Continuous when enabling conditions met.

TYPICAL DURATION:
One minute

DASH LAMPS:
1. MIL
2. CEL

ENGINE REACTION:
Regen inhibit and 10% engine derate.

VERIFICATION:
Low temperature regen.

NOTE: If 3242-3, 3242-4, 3242-8, 3250-3, 3250-4, or 3250-8 present, fix those first.

PROBABLE CAUSES:
1. Compare DOC inlet, DOC outlet, and DPF outlet. They should be wihin 45 degrees of each other.
2. DOC inlet temperature sensor.
3. DOC inlet temperature sensor connector/harness.
4. DOC outlet temperature sensor.
5. DOC outlet temperature sensor connector/harness.