Safe to driveTo the nearest safe stop
J1939 code SPN 126. Below — how the fault is worded at the factory by Renault Trucks and ZF AS-Tronic, and what the second half of the code (FMI) means in the standard.
| FMI 3 | Air pressure signal fault. Repair: Switch the ignition off, switch it on again and repeat the test. If the fault persists, replace the control unit. |
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 3 | No signal from the pressure sensor. |
| SPN 126 FMI 3126/3 · 126.3 | voltage above normal or shorted high |
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.