SPN 1811 FMI 9 — Cab controller J1939 message lost
What it means: Cab controller J1939 message lost.
How serious / can you keep driving: Serious. Power derate likely — plan to stop soon.
Check first: Check bus
Don't risk it — look up listed providers near you and give them this SPN/FMI when you call.
Listed providers nearest Macon, GA
Closest first. Tell them SPN 1811 FMI 9 and what the truck is doing. RoadService.app lists these providers and does not employ them or carry out the repair.
- 0.0 mi away — based in Macon, GA · (478) 538-3245
- 0.0 mi away — based in Macon, GA · (478) 216-8330
- 0.0 mi away — based in Macon, GA · (706) 536-3376
Applies to: Bendix · Wabco
What SPN 1811 FMI 9 means
Cab controller J1939 message lost.
How serious is it?
Serious. Power derate likely — plan to stop soon.
Most likely causes
- J1939 issue
- BCM issue
- J1939
- BCM
First moves (roadside)
- Check bus
FAQ
Cab controller J1939 message lost.
Serious — Power derate likely — plan to stop soon.
The most common cause is: J1939 issue. Other possibilities include BCM issue; J1939; BCM.
Power derate likely — plan to stop soon. When in doubt, get a qualified mobile diesel tech on the truck before continuing.
Related codes
Codes that commonly appear alongside SPN 1811 FMI 9, or share the same subsystem.
- Service brake air pressure — primary circuit low (SPN 519 FMI 4)
- Service brake air pressure — secondary circuit low (SPN 520 FMI 4)
- Left front wheel speed sensor erratic (SPN 789 FMI 2)
- Left front wheel speed abnormal signal (SPN 789 FMI 8)
- Right front wheel speed sensor erratic (SPN 790 FMI 2)
- Right front wheel speed abnormal (SPN 790 FMI 8)
- Left rear (LF drive) wheel speed erratic (SPN 791 FMI 2)
- Left rear wheel speed abnormal (SPN 791 FMI 8)
Same symptom: Lost communication
Other datalink faults. A U-code is a network problem and is diagnosed at the datalink, not at the module that went quiet.
- Lost J1939 datalink message from VECU (SPN 1807 FMI 9) · Brakes, ABS & Stability
- ABS Lost Communication with PCM (C0290) · Brakes, ABS & Stability
- Vehicle Speed Signal — Erratic / Lost (SPN 84 FMI 19) · Brakes, ABS & Stability
- Engine Oil Pressure — Extremely Low (SPN 100 FMI 1) · Lubrication
- High Speed CAN Bus Fault (U0001) · Electrical, Charging & Network
- Lost Communication with ECM/PCM (U0100) · Electrical, Charging & Network
Find a mechanic or related guides
General diagnostic guidance for heavy-duty diesel engines (Cummins, Detroit, PACCAR, Volvo, Mack). Not a substitute for a scan-tool diagnosis on your specific truck.