Safe to driveEnough to reach the yard
J1939 code SPN 107. Below — how the fault is worded at the factory by Mercedes-Benz, Renault Trucks and ZF AS-Tronic, and what the second half of the code (FMI) means in the standard.
Mercedes-BenzRenault TrucksZF AS-Tronic
| FMI 0 | Air Filter Restriction High |
| FMI 2 | Air Filter Sensor plausibility error |
| FMI 3 | Air Filter diff.-pressure Sensor or switch shorted to Ubat |
| FMI 4 | Air Filter diff.-pressure Sensor or switch shorted to GND |
| FMI 2 | Clutch sensor supply out of allowed limits. Repair: Run the diagnostic check of the clutch actuator. Check the wiring between the Astronic and the components (X1B/15). Switch the ignition off, switch it on again and repeat the test. If the fault persists, replace the control unit. |
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 2 | Clutch sensor supply voltage out of range (output AU). |
Safe to drive. Below — how much time you have and what happens if you keep going.
Boost is not reaching its target: turbo, intercooler or intake. The engine compensates with mixture and runs hotter than usual.
You will lose pull, burn more fuel and add overheating on long climbs. If you hear a whine or a whistle from the turbo, stop — the wheel is breaking up.
This is an electrical fault: an open, a short or a bad contact in the sensor circuit. The value it measures is most likely fine. You can drive. But until the circuit is repaired this system runs blind and cannot warn you about a real failure.
That said, the manufacturer flags this code as critical — if in doubt, it is safer to stop and check on the spot.
Inspect the air filter and charge-air hoses: leaks and cracks produce exactly these codes.
Scanner threw several codes at once? Paste the whole list — we will show which one is the root cause and which ones simply followed.