Do not driveMinutes
J1939 code SPN 597. Below — how the fault is worded at the factory by International, KAMAZ, Knorr-Bremse EBS, MAN, MAZ, Mercedes-Benz, Renault Trucks, SITRAK and YaMZ, and what the second half of the code (FMI) means in the standard.
InternationalKAMAZKnorr-Bremse EBSMANMAZMercedes-BenzRenault TrucksSITRAKYaMZ
| FMI 0 | Brake Switch — Brake Switch reading above normal range |
| FMI 1 | Brake Switch — Brake Switch reading below normal range |
| FMI 2 | Brake Switch — Brake Switch Inputs Do Not Match |
| FMI 7 | Brake Switch — Brake Switch Stuck Open Or Closed |
| FMI 14 | Brake Switch — Brake switch is stuck in the open or closed position; Brake Switch — Brake switch inputs do not match |
| FMI 2 | Same as above + diagnostic lamp on |
| FMI 9 | Brake switch. K-line code on KamAZ-5490: ADM3 18409. |
| FMI 12 | Brake pedal sensor: faulty/implausible signal |
| FMI 19 | Brake switch. K-line code on KamAZ-5490: ADM3 18419. |
| FMI 5 | Module foot brake switch 1. Short to Ground |
| FMI 6 | Module foot brake, switch on power supply 1. Short Ubat |
| FMI 5 | Module foot brake switch 1 - Short to Ground |
| FMI 6 | Module foot brake switch 1 - Short to power supply |
| FMI 2 | Cruise control lamp activation without braking - Cruise control lamp lit. Blink code: 2-2-3. Repair: Service function. No action required. |
| FMI 12 | Brake pedal sensor circuit fault - Signal invalid. Blink code: 2-2-3. Repair: Check the brake pedal position sensor and its wiring. |
| FMI 13 | J1939 Service Brake Switch Signal from Source CCVS1, CCVS2 or CCVS3 missing or not available = SNA (signal not available) |
| FMI 17 | Brake pedal switch |
| FMI 2 | Brake signal implausible or the signal line is disconnected. Scan tool code: P0504. Effect: Torque may be limited. |
| FMI 7 | Brake signal not plausible. Scan tool code: P0504. Effect: Loss of communication with the modules, some functions are disabled. |
| FMI 8 | Brake signal not plausible. Scan tool code: P0504. Effect: Loss of communication with the modules, some functions are disabled. |
| FMI 11 | Cruise control released: no valid brake signal. Scan tool code: P0504. Effect: Loss of communication with the modules, some functions are disabled. |
| FMI 12 | Brake signal not plausible. Scan tool code: P0504. Effect: Loss of communication with the modules, some functions are disabled. |
| FMI 19 | Brake signal error: CAN frame timeout. Scan tool code: P0571. Effect: Loss of communication with the modules, some functions are disabled. |
| FMI 22 | Implausible engine brake signal. Scan tool code: P04D3. Effect: Loss of communication with the modules, some functions are disabled. |
| FMI 2 | Cruise control lamp activated without braking (Cruise control lamp illuminated). Blink code: 2-2-3. Repair: Service function. No action required. |
| FMI 12 | Brake pedal sensor circuit fault (Signal incorrect). Blink code: 2-2-3. Repair: Check the brake pedal position sensor and its wiring. |
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.
This code is often not the fault itself but a knock-on. If any of these is in the same readout, start with it:
Scanner threw several codes at once? Paste the whole list — we will show which one is the root cause and which ones simply followed.