Do not driveMinutes
J1939 code SPN 797. Below — how the fault is worded at the factory by Bendix ABS/ESP, Meritor (ex-WABCO), Renault Trucks and WABCO ABS/ESC, and what the second half of the code (FMI) means in the standard.
Bendix ABS/ESPMeritor (ex-WABCO)Renault TrucksWABCO ABS/ESC
| FMI 3 | DA Left PMV HLD Solenoid Shorted to Voltage; DA Right PMV REL Solenoid Shorted to Voltage |
| FMI 4 | DA Left PMV HLD Solenoid Shorted to Ground; DA Left PMV REL Solenoid Shorted to Ground |
| FMI 5 | DA Left PMV CMN Open Circuit; DA Left PMV HLD Solenoid Open Circuit; DA Left PMV REL Solenoid Open Circuit |
| FMI 13 | DA Left PMV Configuration Error |
| FMI 3 | Failure detection 'ShortUb' at AbsInlet/ AbsOutlet (Drive Axle Left) |
| FMI 4 | Failure detection 'ShortGnd' at AbsInlet/AbsOutlet (Drive Axle Left) |
| FMI 5 | Failure detection 'Interruption' at AbsInlet/AbsOutlet (Drive Axle Left) |
| FMI 13 | Failure detection 'OverEquipped' at AbsInlet/AbsOutlet (Drive Axle Left) |
| FMI 2 | ABS valve, rear left, does not meet requirements. Repair: Check that the ABS valve is the correct one. |
| FMI 3 | ABS valve, rear left, inlet and outlet valves, short circuit. Repair: Check the continuity of the ABS valve wiring (X4/1, X4/2, X4/3). |
| FMI 4 | ABS valve, rear left, inlet and outlet valves, short to ground. Repair: Check the continuity of the ABS valve wiring (X4/1, X4/2, X4/3). |
| FMI 5 | ABS valve, rear left, short on one of the supply wires. Repair: Check the continuity of the ABS valve wiring (X4/1, X4/2, X4/3). |
| FMI 12 | Rear circuit pneumatic fault or module internal fault. Repair: Check the module inlet and outlet for air leaks. Check the air lines for contamination and kinks. Check the exhaust at the valve and at the module with a PC. Check the minimum pressure switches. |
| FMI 3 | Shorted to UBATT |
| FMI 5 | Open Circuit |
| FMI 6 | Shorted to Ground |
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.