Caterpillar Fault Code
Free · no signupSPN 4364 FMI 18
Emission Derate.
System
Not specified
Symptom
Emission Derate.
Diagnosis & fix steps
LOGIC: DEF Quality Contaminated.
ACTION: Drain DEF tank and refill with fresh fluid. Clear the "Inducement" timers.
Red Seal field insights
Often triggered by "old" DEF that has sat in a machine for months. DEF has a shelf life of about 1 year; heat in the Philippines or Middle East cuts that in half.
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