Safe to driveDrivable, but watch it yourself
SPN 49 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), Renault Trucks and ZF AS-Tronic, and what the second half of the code (FMI) means.
Meritor (ex-WABCO)Renault TrucksZF AS-Tronic
| FMI 3 | Power Amp. Out Valve Right Front — Shorted to Battery |
| FMI 5 | Power Amp. Out Valve Right Front — Open Circuit |
| FMI 6 | Power Amp. Out Valve Right Front — Short to Ground |
| FMI 10 | Open circuit. 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 10 | Fault on transmission brake valve Y1 output 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.