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SPN 3842 — Auxiliary Input/Output #19

Safe to driveDrivable, but watch it yourself

J1939 code SPN 3842. Below — how the fault is worded at the factory by Mercedes-Benz, and what the second half of the code (FMI) means in the standard.

Mercedes-Benz

FMI 3Analog Ground 3/02 Circuit shorted to Ubat
FMI 4Analog Ground 3/02 Circuit shorted to GND
FMI 5Analog Ground 3/02 Open Circuit (broken wire, terminal floating)

What FMI means in J1939

SPN 3842 FMI 33842/3 · 3842.3voltage above normal or shorted high
SPN 3842 FMI 43842/4 · 3842.4voltage below normal or shorted to ground
SPN 3842 FMI 53842/5 · 3842.5current below normal or open circuit

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

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