Engine Speed / Crankshaft Sensor - Data Erratic, Intermittent, or Incorrect
The CAT-CID190-FMI2 (Caterpillar) diesel fault code means: Engine Speed / Crankshaft Sensor - Data Erratic, Intermittent, or Incorrect. This is a serious severity code.
- Keep driving?
- Yes, but fix soon
- DIY difficulty
- intermediate
- Estimated cost
- $200-$800
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Common Symptoms
- Intermittent Check Engine Light
- Erratic or fluctuating signal on CAT ET
- Possible stumble or momentary power loss
Probable Causes (Ranked by Likelihood)
- Intermittent wiring fault from chafe or loose pin Very Likely
- Failing sensor producing noise Likely
- EMI or ground noise or bad ECM ground Possible
Step-by-Step Diagnostic Procedure
Wiggle-test the harness and connector while watching live data on CAT ET for dropouts.
Back-probe the signal pin and measure during operation; erratic readings confirm the circuit or sensor.
Inspect connector pin tension and replace the sensor if harness checks good.
Frequently Asked Questions
What does CAT code CID190-FMI2 mean?
CAT code CID190-FMI2 (Engine Speed / Crankshaft Sensor - Data Erratic, Intermittent, or Incorrect) is a serious-severity fault on Caterpillar on-highway diesel engines. CID 190 is the Engine Speed / Crankshaft Sensor, measuring primary crank speed signal. FMI 2 (Data Erratic, Intermittent, or Incorrect) 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 CID190-FMI2?
Short distances may be acceptable, but running long with this fault risks progressive damage or forced derate. Address promptly.
How much does it cost to fix CAT CID190-FMI2?
Typical repair is $200-$800. 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.