Do not driveTo the nearest safe stop
J1939 code SPN 108. Below — how the fault is worded at the factory by DAF, Dongfeng, Isuzu, KAMAZ, MAZ, Renault Trucks, SITRAK, YaMZ and ZF AS-Tronic, and what the second half of the code (FMI) means in the standard.
DAFDongfengIsuzuKAMAZMAZRenault TrucksSITRAKYaMZZF AS-Tronic
| FMI 2 | Air pressure F609 implausible (extended period) |
| FMI 3 | Air pressure F609 voltage too high at ECU pin A20 (extended period) |
| FMI 4 | Air pressure F609 voltage too low at ECU pin A20 (extended period) |
| FMI 2 | Incorrect atmospheric pressure signal |
| FMI 3 | Short circuit to power supply of the atmospheric pressure sensor. Scan tool code: P2229. |
| FMI 4 | Short circuit to ground or open circuit of the atmospheric pressure sensor. Scan tool code: P2228. |
| FMI 3 | Barometric pressure sensor fault (low voltage fault) (P0107) |
| FMI 4 | Barometric pressure sensor fault (high voltage fault) (P0108) |
| FMI 0 | Atmospheric pressure sensor: physical range limit |
| FMI 1 | Atmospheric pressure sensor: physical range limit |
| FMI 2 | Atmospheric pressure sensor |
| FMI 3 | Atmospheric pressure sensor |
| FMI 4 | Atmospheric pressure sensor |
| FMI 12 | Atmospheric pressure sensor |
| FMI 2 | Atmospheric pressure sensor circuit fault - Reading inconsistent with the boost pressure reading. Blink code: 2-3-2. Power will be reduced. Repair: Check the sensor and its wiring. |
| FMI 3 | Atmospheric pressure sensor circuit fault - Voltage above allowed. Blink code: 2-3-2. Power will be reduced. Repair: Check the sensor and its wiring. |
| FMI 4 | Atmospheric pressure sensor circuit fault - Voltage below allowed. Blink code: 2-3-2. Power will be reduced. Repair: Check the sensor and its wiring. |
| FMI 12 | Atmospheric pressure sensor circuit fault - CAN bus signal implausible. Blink code: 2-3-2. Power will be reduced. Repair: Check the sensor and its wiring. |
| FMI 0 | Gear selector lever error. Repair: Check the joystick. Check the CAN communication (X1A/8, X1A/12, X1A/13, X1A/14). Switch the ignition off, switch it on again and repeat the test. If the fault persists, replace the control unit. |
| FMI 0 | High atmospheric (barometric) pressure |
| FMI 1 | Low atmospheric (barometric) pressure |
| FMI 3 | Ambient pressure sensor voltage above the upper limit. Scan tool code: P2229. |
| FMI 4 | Ambient pressure sensor voltage below the lower limit. Scan tool code: P2228. |
| FMI 12 | Ambient pressure sensor failed its self-diagnosis. Scan tool code: P2226. Effect: Injection correction by air temperature is wrong. |
| FMI 19 | Ambient pressure signal error on the CAN bus. Effect: Loss of communication with the modules, some functions are disabled. |
| FMI 22 | Ambient pressure above the upper limit. Scan tool code: P2226. |
| FMI 23 | Ambient pressure below the lower limit. Scan tool code: P2226. |
| FMI 24 | Ambient pressure sensor voltage above the upper limit. Scan tool code: P8745. |
| FMI 25 | Ambient pressure sensor voltage below the lower limit. Scan tool code: P8744. |
| FMI 2 | Atmospheric pressure sensor circuit fault (Reading inconsistent with boost pressure reading). Blink code: 2-3-2. Power will be reduced. Repair: Check the sensor and its wiring. |
| FMI 3 | Atmospheric pressure sensor circuit fault (Voltage above allowable limit). Blink code: 2-3-2. Power will be reduced. Repair: Check the sensor and its wiring. |
| FMI 4 | Atmospheric pressure sensor circuit fault (Voltage below allowable limit). Blink code: 2-3-2. Power will be reduced. Repair: Check the sensor and its wiring. |
| FMI 12 | Atmospheric pressure sensor circuit fault (CAN bus signal implausible). Blink code: 2-3-2. Power will be reduced. Repair: Check the sensor and its wiring. |
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 8 | Mechanical fault in the rotary switch. |
Do not drive. Stop as soon as it’s safe to do so — don’t keep going.
The code is flagged critical: the manufacturer considers it unsafe to keep driving without checking.
This code alone cannot say what will fail next, so stop at the first safe opportunity and look at it on the spot.
That said, the manufacturer flags this code as critical — if in doubt, it is safer to stop and check on the spot.
Scanner threw several codes at once? Paste the whole list — we will show which one is the root cause and which ones simply followed.