Group 28 Engine Control Module (ECM) Diagnostic Trouble Codes (DTCs) ECM SPN 4354, Aftertreatment Diesel Exhaust Fluid (DEF) Line Heater 1 MID 128 PSID 103 ECM SPN 4356, Aftertreatment Diesel Exhaust Fluid (DEF) Line Heater 3 MID 128 PSID 102 ECM SPN 4374, Aftertreatment Diesel Exhaust Fluid (DEF) Pump Motor Speed MID 128 PSID 87 79 Type of fault: FMI Description: Fault Condition: Possible Symptoms: Possible Cause:
FMI 3 • Voltage above normal, or shorted to high source • Circuit shorted + • N/A • Faulty harness • Faulty connector • Aftertreatment DEF line heater 1 failure FMI 4 • Voltage below normal, or shorted to low source • Circuit shorted – • N/A • Faulty harness • Faulty connector • Aftertreatment DEF line heater 1 failure FMI 5 • Current below normal or open circuit • Open circuit • N/A • Faulty harness • Faulty connector • Aftertreatment DEF line heater 1 failure Type of fault: FMI Description: Fault Condition: Possible Symptoms: Possible Cause:
FMI 3 • Voltage above normal, or shorted to high source • Circuit shorted + • N/A • Faulty harness • Faulty connector • Aftertreatment DEF line heater 3 failure FMI 4 • Voltage below normal, or shorted to low source • Circuit shorted – • N/A • Faulty harness • Faulty connector • Aftertreatment DEF line heater 3 failure FMI 5 • Current below normal or open circuit • Open circuit • N/A • Faulty harness • Faulty connector • Aftertreatment DEF line heater 3 failure Type of fault: FMI Description: Fault Condition: Possible Symptoms: Possible Cause:
FMI 1 • Data valid but below normal operational range - Most severe level • Slow pump speed • MIL illuminated • No Aftertreatment Diesel Exhaust Fluid (DEF) dosing • Faulty harness • Faulty connector • Aftertreatment DEF pump assembly failure