SPN 793 FMI 11 — Shift lever — root cause unknown
What it means: Shift lever — root cause unknown.
How serious / can you keep driving: Serious. Power derate likely — plan to stop soon.
Check first: Check sensor
Don't risk it — look up listed providers near you and give them this SPN/FMI when you call.
Listed providers nearest Oklahoma City, OK
Closest first. Tell them SPN 793 FMI 11 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 Oklahoma City, OK · (405) 551-3320
- 0.0 mi away — based in Oklahoma City, OK · (405) 682-1362
- 0.0 mi away — based in Oklahoma City, OK · (405) 632-6010
Applies to: Eaton
What SPN 793 FMI 11 means
Shift lever — root cause unknown.
How serious is it?
Serious. Power derate likely — plan to stop soon.
Most likely causes
- Lever position sensor
- Wiring
First moves (roadside)
- Check sensor
FAQ
Shift lever — root cause unknown.
Serious — Power derate likely — plan to stop soon.
The most common cause is: Lever position sensor. Other possibilities include Wiring.
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 793 FMI 11, or share the same subsystem.
- Left tag/pusher wheel speed erratic (SPN 793 FMI 2)
- Main shaft speed erratic (SPN 160 FMI 2)
- Input shaft speed erratic (SPN 161 FMI 2)
- Transmission output retarder speed erratic (SPN 162 FMI 2)
- Trans oil temperature very high (SPN 177 FMI 0)
- Trans oil temperature voltage high (SPN 177 FMI 3)
- Trans oil temperature voltage low (SPN 177 FMI 4)
- Engine speed signal abnormal update rate (SPN 190 FMI 9)
Same symptom: Won't shift
Other codes that show up as a truck that won't take a gear or drops out of one.
- Transmission output shaft speed erratic (SPN 191 FMI 2) · Drivetrain & Transmission
- Transmission output retarder position erratic (SPN 2919 FMI 2) · Drivetrain & Transmission
- Retarder not responding (SPN 2920 FMI 7) · Drivetrain & Transmission
- Gear selection failure (SPN 749 FMI 7) · Drivetrain & Transmission
- Range shift signal erratic (SPN 753 FMI 2) · Drivetrain & Transmission
- Shift finger not moving to commanded position (SPN 787 FMI 7) · Drivetrain & Transmission
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.