Updated: 2026-11-14
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2203 codes decoded from the factory tables of 22 makes. Below — the full list by system and the standard FMI table: with it the code reads whole, not by halves.
The SPN number says what is faulty, FMI says what exactly is wrong with it. The second half of the code is the same for every make — that is the J1939 standard.
| FMI 0 | data above normal range (most severe level) |
| FMI 1 | data below normal range (most severe level) |
| FMI 2 | data erratic or intermittent |
| FMI 3 | voltage above normal or shorted high |
| FMI 4 | voltage below normal or shorted to ground |
| FMI 5 | current below normal or open circuit |
| FMI 6 | current above normal or grounded circuit |
| FMI 7 | mechanical system not responding |
| FMI 8 | abnormal frequency or pulse width |
| FMI 9 | abnormal update rate |
| FMI 10 | abnormal rate of change |
| FMI 11 | root cause not known |
| FMI 12 | faulty device or component |
| FMI 13 | calibration out of range |
| FMI 14 | manufacturer-specific instructions |
| FMI 15 | above normal — low severity |
| FMI 16 | above normal — moderate severity |
| FMI 17 | below normal — low severity |
| FMI 18 | below normal — moderate severity |
| FMI 19 | error in received network data |
| FMI 20 | data drifted high |
| FMI 21 | data drifted low |
| FMI 31 | condition exists (see manufacturer description) |
Know the code number? Type it into the search — or paste the whole list from the scanner and we will show which fault is the real one.