Safe to driveTo the nearest safe stop
J1939 code SPN 4077. Below — how the fault is worded at the factory by Knorr-Bremse EBS and MAN, and what the second half of the code (FMI) means in the standard.
| FMI 0 | Pressure control module not configured. Undefined fault |
| FMI 0 | Pressure control module not configured - Undefined fault |
| SPN 4077 FMI 04077/0 · 4077.0 | data above normal range (most severe level) |
Safe to drive. Below — how much time you have and what happens if you keep going.
Fuel is not arriving in the right amount or at the right pressure. It shows up first on climbs and under load.
You will most likely stall out on the road, and may not restart on the shoulder. A clogged filter or water in the tank you can nurse to a shop; a failing injection pump you cannot.
That said, the manufacturer flags this code as critical — if in doubt, it is safer to stop and check on the spot.
Check the fuel filter and water trap, drain the water. In cold weather, suspect fuel waxing.
Scanner threw several codes at once? Paste the whole list — we will show which one is the root cause and which ones simply followed.