Do not driveTo the nearest safe stop
J1939 code SPN 188. Below — how the fault is worded at the factory by SITRAK and ZF AS-Tronic, and what the second half of the code (FMI) means in the standard.
| FMI 0 | Engine speed above the upper limit while the high-idle demand is active. Scan tool code: P0507. Effect: Torque may be limited. |
| FMI 1 | Rail pressure control time exceeded. Scan tool code: P015E. Effect: Power limited, the engine runs unevenly. |
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 0 | Fault in the main control unit, or the control unit and software are incompatible. |
| SPN 188 FMI 0188/0 · 188.0 | data above normal range (most severe level) |
| SPN 188 FMI 1188/1 · 188.1 | data below normal range (most severe level) |
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.