Engine Oil Pressure Sensor - Data Valid But Below Normal Operating Range
The CAT-CID100-FMI1 (Caterpillar) diesel fault code means: Engine Oil Pressure Sensor - Data Valid But Below Normal Operating Range. This is a serious severity code.
- Keep driving?
- No -- stop driving
- DIY difficulty
- intermediate
- Estimated cost
- $300-$3000
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Common Symptoms
- Warning lamp or shutdown lamp
- Measured value below expected operating range
- Engine protect mode possible
Probable Causes (Ranked by Likelihood)
- Actual measured value truly low from mechanical issue Very Likely
- Sensor drift or out of calibration Likely
- Restriction, leak, or worn component in the measured system Likely
Step-by-Step Diagnostic Procedure
Confirm with CAT ET and note actual sensor reading versus expected range.
Verify the physical system (oil pressure, fuel pressure, etc.) with a mechanical gauge.
If mechanical reading matches sensor, fix the underlying mechanical fault.
If mechanical reading is normal but sensor reads low, replace sensor after verifying wiring and supply.
Frequently Asked Questions
What does CAT code CID100-FMI1 mean?
CAT code CID100-FMI1 (Engine Oil Pressure Sensor - Data Valid But Below Normal Operating Range) is a serious-severity fault on Caterpillar on-highway diesel engines. CID 100 is the Engine Oil Pressure Sensor, measuring engine oil pressure. FMI 1 (Data Valid But Below Normal Operating Range) indicates the specific fault mode. Use CAT ET to confirm before replacing parts. Diagnose with CAT ET (Electronic Technician) software.
Can I drive my truck with CAT code CID100-FMI1?
No. This fault can trigger engine protect mode, derate, or cause further damage. Park and diagnose before operating.
How much does it cost to fix CAT CID100-FMI1?
Typical repair is $300-$3000. Sensor / wiring fixes fall at the low end; injector, HEUI pump, turbo, or aftertreatment work falls at the high end. CAT dealer labor often requires CAT ET for calibration and parameter programming.
Sources
This page is built from documented references. Verify against your own service info before repair work.