Safe to driveDrivable, but watch it yourself
SPN 8 is a manufacturer number outside the standard J1939 table: different makes can put different things under it. Below — how it is worded by Ford Trucks and ZF AS-Tronic, and what the second half of the code (FMI) means.
Ford Trucks/Ecotorq writes fault numbers in its own format: the code in the table below is a Ford code (hexadecimal, zero-padded), not a J1939 SPN. It matches the standard only where the signal itself is standard, and usually matches the title of this page by digit alone.
| FMI 2 | Vehicle speed inconsistent high. FODP code (scan tool): P062C-00. |
| FMI 5 | Front wheel speed information CAN message communication error. FODP code (scan tool): P1503-00. |
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 5 | Short circuit to ground on valve Y8 output (rear splitter group). For AS Tronic 2: engaging the slow group is not possible. For AS Tronic mid: engaging the fast group is not possible. |
| SPN 8 FMI 28/2 · 8.2 | data erratic or intermittent |
| SPN 8 FMI 58/5 · 8.5 | current below normal or open circuit |
Safe to drive. Below — how much time you have and what happens if you keep going.
This is an electrical fault: an open, a short or a bad contact in the sensor circuit. The value it measures is most likely fine.
You can drive. But until the circuit is repaired this system runs blind and cannot warn you about a real failure.
Scanner threw several codes at once? Paste the whole list — we will show which one is the root cause and which ones simply followed.