Do not driveTo the nearest safe stop
SPN 520536 is a manufacturer number outside the standard J1939 table: different makes can put different things under it. Below — how it is worded by Meritor (ex-WABCO), and what the second half of the code (FMI) means.
| FMI 0 | Overheating at ABS Valve (Trailer Control)/ High Level |
| FMI 15 | Overheating at ABS Valve (Trailer Control)/ Low Level |
| SPN 520536 FMI 0520536/0 · 520536.0 | data above normal range (most severe level) |
| SPN 520536 FMI 15520536/15 · 520536.15 | above normal — low severity |
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.