Do not driveMinutes
J1939 code SPN 1243. Below — how the fault is worded at the factory by Mercedes-Benz and Meritor (ex-WABCO), and what the second half of the code (FMI) means in the standard.
| FMI 14 | ABS fault restricts automatic gear selection functionality |
| FMI 12 | ABS Function Is Not Fully Operational |
| SPN 1243 FMI 121243/12 · 1243.12 | faulty device or component |
| SPN 1243 FMI 141243/14 · 1243.14 | manufacturer-specific instructions |
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.