Do not driveMinutes
J1939 code SPN 603. 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 | Module foot brake switch 2. Short to Ground |
| FMI 6 | Module foot brake switch 2. Short to power supply Ubat |
| FMI 5 | Module foot brake switch 2 - Short to Ground |
| FMI 6 | Module foot brake switch 2 - Short to power supply |
| SPN 603 FMI 5603/5 · 603.5 | current below normal or open circuit |
| SPN 603 FMI 6603/6 · 603.6 | current above normal or grounded circuit |
Do not drive. Stop as soon as it’s safe to do so — don’t keep going.
Part of the brake circuit or ABS/EBS is out of service. The pedal may still feel normal — until the first emergency stop or descent.
Next comes longer stopping distance, a skid on a slick surface, failure on a long downgrade. This is the case where "I will take it slow" does not work.
Let the air system build to working pressure and listen for leaks. Don’t drive with faulty brakes.
Scanner threw several codes at once? Paste the whole list — we will show which one is the root cause and which ones simply followed.