Safe to driveTo the nearest safe stop
J1939 code SPN 525. Below — how the fault is worded at the factory by Mercedes-Benz and SITRAK, and what the second half of the code (FMI) means in the standard.
| FMI 7 | Transmission gear selection switch reports internal error |
| FMI 19 | Incorrect data length of the ETC1 CAN frame. Effect: Loss of communication with the modules, some functions are disabled. |
| SPN 525 FMI 7525/7 · 525.7 | mechanical system not responding |
| SPN 525 FMI 19525/19 · 525.19 | error in received network data |
Safe to drive. Below — how much time you have and what happens if you keep going.
The gearbox or clutch has gone into limp mode: some gears may be unavailable and an automated box may stop shifting under load.
The main risk is being left on a climb with no gear and rolling back. Do not take a loaded truck into the hills; reaching level ground and a shop is fine.
Scanner threw several codes at once? Paste the whole list — we will show which one is the root cause and which ones simply followed.