Safe to driveTo the nearest safe stop
J1939 code SPN 36. Below — how the fault is worded at the factory by Ford Trucks and ZF AS-Tronic, and what the second half of the code (FMI) means in the standard.
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 0 | Urea Dosing System Leak. FODP code (scan tool): P20F6-00. |
| FMI 1 | Urea Temperature Is Very High. FODP code (scan tool): P24FF-00. |
| FMI 2 | Urea Dosing System Filter Clogged. FODP code (scan tool): P20F6-01. |
ZF AS-Tronic uses its own fault numbering: the number in the table below is an internal ZF code, not a J1939 SPN. It matches the title of this page by digit only and means something different.
| FMI 10 | Fault on valve Y4 output circuit (range selector valve). |
Safe to drive. Below — how much time you have and what happens if you keep going.
The gearbox or clutch has gone into limp mode: some gears may be unavailable and an automated box may stop shifting under load.
The main risk is being left on a climb with no gear and rolling back. Do not take a loaded truck into the hills; reaching level ground and a shop is fine.
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.