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SPN 54 — Transmission Synchronizer Brake Value

Do not driveMinutes

J1939 code SPN 54. Below — how the fault is worded at the factory by Ford Trucks, Renault Trucks and ZF AS-Tronic, and what the second half of the code (FMI) means in the standard.

Ford TrucksRenault TrucksZF AS-Tronic

Ford Trucks

Ford Trucks/Ecotorq writes fault numbers in its own format: the code in the table below is a Ford code (hexadecimal, zero-padded), not a J1939 SPN. It matches the standard only where the signal itself is standard, and usually matches the title of this page by digit alone.

FMI 19Engine control unit (EDS) transmits faulty signal

Renault Trucks

FMI 10Open circuit. Repair: Check the joystick unit and the gearbox output mode sensor. Check the wiring between the Astronic and the component (X1A/11, X1B/18). If the fault persists, replace the control unit.

ZF AS-Tronic

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 10Fault on ADVP/ADVP1 output (power supply for output shaft 1 speed sensor).

What FMI means in J1939

SPN 54 FMI 1054/10 · 54.10abnormal rate of change
SPN 54 FMI 1954/19 · 54.19error in received network data

Can I keep driving

Do not drive. Stop as soon as it’s safe to do so — don’t keep going.

What happens if you keep driving

Time you have: Minutes

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.

What to check on the spot

Let the air system build to working pressure and listen for leaks. Don’t drive with faulty brakes.

Nearby: 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.