Do not driveTo the nearest safe stop
SPN 1 is a manufacturer number outside the standard J1939 table: different makes can put different things under it. Below — how it is worded by Ford Trucks and Meritor (ex-WABCO), and what the second half of the code (FMI) means.
Ford Trucks/Ecotorq writes fault numbers in its own format: the code in the table below is a Ford code (hexadecimal, zero-padded), not a J1939 SPN. It matches the standard only where the signal itself is standard, and usually matches the title of this page by digit alone.
| FMI 1 | Immobilizer Error – Incompatible Key. FODP code (scan tool): P0513-00. |
| FMI 2 | Immobilizer Error – Key Knowledge Reading. FODP code (scan tool): P1259-00. |
| FMI 3 | Immobilizer Error – Key Knowledge Writing. FODP code (scan tool): P1623-00. |
| FMI 1 | Left Front Wheel Speed Sensor — Air Gap |
| FMI 5 | Left Front Wheel Speed Sensor — Impedance |
| FMI 7 | Left Front Wheel Speed Sensor — Tone Ring |
| FMI 8 | Left Front Wheel Speed Sensor — No Trigger Detected |
| FMI 11 | Left Front Wheel Speed Sensor — Brake Chatter |
Do not drive. Stop as soon as it’s safe to do so — don’t keep going.
The code is flagged critical: the manufacturer considers it unsafe to keep driving without checking.
This code alone cannot say what will fail next, so stop at the first safe opportunity and look at it on the spot.
That said, the manufacturer flags this code as critical — if in doubt, it is safer to stop and check on the spot.
Scanner threw several codes at once? Paste the whole list — we will show which one is the root cause and which ones simply followed.