Caterpillar Aftertreatment Fault Codes

CAT fault code 1761-17 commonly relates to diesel exhaust fluid level or a DEF level signal that is below the expected range.

CAT codes listed as 3360/3820 generally point toward the DEF supply, DEF quality, DEF tank, or SCR dosing system depending on the exact FMI shown in Cat ET.

CAT codes listed as 3361/3821 commonly belong to the DEF dosing or SCR control side of the aftertreatment system.

CAT fault code 3474-31 is typically associated with aftertreatment regeneration or ARD-related operation.

CAT fault code 3701-15 commonly indicates an aftertreatment condition that is above normal but at a least-severe level, often connected with DPF soot load, regeneration need, or aftertreatment restriction.

CAT fault code 3701-16 usually represents a more serious aftertreatment condition than 3701-15, with the measured or calculated value above normal at a moderate severity level.

CAT fault code 3719-0 is generally an aftertreatment soot-load or DPF restriction code at a high-severity level.

CAT fault code 4377-12 commonly points to an aftertreatment DEF/SCR component or controller problem where the device is not operating correctly.

CAT fault code 5246-16 is commonly used as an aftertreatment inducement or emissions-related derate code.

CAT event code E1217 should be handled as an aftertreatment event code that requires confirmation in Cat ET or SIS for the exact engine and application.

FMI is not a fault code by itself.

SPN is not a complete fault code by itself.

ARD is not a fault code by itself.

CAT fault code 3391-5 is commonly associated with an ARD or aftertreatment regeneration control circuit where current is below normal or the circuit is open.

CAT fault code 3413-6 generally indicates an ARD or aftertreatment control circuit with current above normal or a shorted condition.

CAT fault code 3473-31 commonly relates to an aftertreatment fuel or ARD system condition that is not meeting expected operation.

CAT fault code 3480-17 is commonly tied to aftertreatment fuel pressure or ARD fuel delivery being below the expected range.

CAT fault code 3480-18 generally indicates an aftertreatment or ARD fuel-pressure condition below normal at a moderate severity level.

CAT fault code 3484-5 is generally an aftertreatment or ARD control circuit fault where current is below normal or the circuit is open.

CAT fault code 3484-6 usually indicates an aftertreatment or ARD control circuit with current above normal, commonly caused by a shorted component or shorted wiring.

CAT fault code 3487-5 commonly points to an ARD or aftertreatment circuit with low current or an open circuit.

CAT fault code 3715-31 commonly relates to regeneration being needed, inhibited, or not completed under required conditions.

CAT fault code 3719-16 generally indicates an aftertreatment soot-load or DPF restriction condition above normal at a moderate severity level.

CAT event code E1026 should be verified in Cat ET or SIS for the exact engine and emissions package.