Safe to driveDrivable, but watch it yourself
J1939 code SPN 746. 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 5 | Differential lock valve. Short to Ground |
| FMI 6 | Differential lock valve. Short to power supply Ubat |
| FMI 5 | Differential lock valve - Short to Ground |
| FMI 6 | Differential lock valve - Short to power supply |
| SPN 746 FMI 5746/5 · 746.5 | current below normal or open circuit |
| SPN 746 FMI 6746/6 · 746.6 | current above normal or grounded circuit |
Safe to drive. Below — how much time you have and what happens if you keep going.
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.
Scanner threw several codes at once? Paste the whole list — we will show which one is the root cause and which ones simply followed.