SPN 4078 — Module trailer control valve inlet (Knorr-Bremse EBS and MAN)

Safe to driveDrivable, but watch it yourself

SPN 4078 is a manufacturer number outside the standard J1939 table: different makes can put different things under it. Below — how it is worded by Knorr-Bremse EBS and MAN, and what the second half of the code (FMI) means.

Knorr-Bremse EBS

FMI 6	Module trailer control valve inlet. Short to power supply Ubat
FMI 7	Module trailer control valve inlet. Short
FMI 9	Module trailer control valve inlet. Faulty devices
FMI 10	Module trailer control valve inlet. Open

MAN

FMI 6	Module trailer control valve inlet - Short to power supply
FMI 7	Module trailer control valve inlet - Short
FMI 9	Module trailer control valve inlet - Faulty
FMI 10	Module trailer control valve inlet - Open

What FMI means in J1939

SPN 4078 FMI 64078/6 · 4078.6	current above normal or grounded circuit
SPN 4078 FMI 74078/7 · 4078.7	mechanical system not responding
SPN 4078 FMI 94078/9 · 4078.9	abnormal update rate
SPN 4078 FMI 104078/10 · 4078.10	abnormal rate of change

Can I keep driving

Safe to drive. Below — how much time you have and what happens if you keep going.

What happens if you keep driving

Time you have: Drivable, but watch it yourself

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.

Nearby: other

• SPN 4071
• SPN 4072ESP sensor power
• SPN 4073Module foot brake power
• SPN 4074
• SPN 4075
• SPN 4079Module trailer control outlet valve
• SPN 4080Module trailer management, backup valve
• SPN 4081Module trailer control pressure sensor power
• SPN 4083
• SPN 4084

Scanner threw several codes at once? Paste the whole list — we will show which one is the root cause and which ones simply followed.