What this code means

Component / fault: ATD.
Reported detail: active regeneration inhibited due to low exhaust temperature.
FMI 14 in the SAE J1939 / Caterpillar CDL convention means: Special instructions — see the full FMI reference table.

On a Caterpillar display this code may appear as MID/CID 311 with FMI 14, or in the older PID/SID style. Wording of the reported detail follows the public Caterpillar fault-code listing cited below.

First checks (general, for this failure type)

Special instructions apply. This code cannot be diagnosed generically; follow the model-specific procedure in the service manual.

These are general electrical checks for FMI 14 faults, not a substitute for the model-specific test procedure. If the fault is active and the machine is derated or shut down, follow the service manual for your model and serial prefix.

Need the part?

If the checks point to a failed sensor, solenoid or harness part, send us the code (311 / FMI 14), the machine model and serial number — we quote genuine and OEM replacement parts for export.