CAT Fault Code

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SPN 100 FMI 3

Low oil pressure warning on dash; Possible engine derate; Gauge pinned to maximum or reading zero.

System

Not specified

Symptom

Low oil pressure warning on dash; Possible engine derate; Gauge pinned to maximum or reading zero.

Diagnosis & fix steps

LOGIC: Open circuit/Short to 5V. ACTION: Check oil level. Unplug sensor; verify 5V ref and ground. Jumper Signal to Ground to check for FMI 4 transition. FIX: Replace sensor or repair harness break near engine block.

Red Seal field insights

If engine is knocking, STOP. If it sounds fine, it is likely a sensor failure.

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