Cummins Fault Code
Free · no signupSPN 3364 (FMI 9/19)
Inducement / Engine Derate.
System
Exhaust (SCR)
Symptom
Inducement / Engine Derate.
Diagnosis & fix steps
LOGIC: Abnormal Update Rate (CAN Comm Error) to the DEF Quality Sensor.
ACTION: Check the 4-pin plug at the DEF Header. Verify 12V/24V power and CAN-Hi/Low (60 Ohms).
Red Seal field insights
Specs: J1939 Data Link.
RED SEAL FIX: On many chassis, the DEF header harness is exposed to road salt. If the "Quality" reading is 0% or toggles to 100%, the sensor's internal board is shorted.
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