FMI 10 — Abnormal rate of change
The value moved faster than physics allows — a jump the ECM knows cannot be real.
Common causes
- Intermittent open or short in the signal circuit
- Failing sensor element
- Loose connector pin making and breaking
- Actual sudden event, such as a burst hose or dropped load
What to test, in order
- Data-log the parameter at a high sample rate and watch for the spike
- Wiggle-test the harness while logging
- Compare with a companion sensor on the same system
- Inspect for a real physical failure before blaming electronics
The reference is free. The diagnosis is Pro.
Every SPN and FMI page on this site stays open — no account needed. Pro members can take the code into Blue Collar AI with the VIN, symptoms and photos, keep per-truck history, and print a work order. $14.99 a month or $99.99 a year.