Home › Caterpillar fault codes › 110 FMI 3
What this code means
Component / fault: Coolant temp sensor.
Reported detail: voltage above normal or shorted high.
FMI 3 in the SAE J1939 / Caterpillar CDL convention means: Voltage above normal, or shorted to high source — see the full FMI reference table.
On a Caterpillar display this code may appear as MID/CID 110 with FMI 3, 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)
Signal voltage is above normal. Look for a short to battery positive in the signal wire, a failed sensor, or water ingress in the connector.
These are general electrical checks for FMI 3 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 (110 / FMI 3), the machine model and serial number — we quote genuine and OEM replacement parts for export.
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Source: public Caterpillar fault code list (thecampingadvisor.com/cat-fault-code-list), cross-checked against the SAE J1939 FMI definitions. Compiled 2026-10-29. No manufacturer affiliation.