P0846 — Trans fluid pressure sensor B circuit
What it means: Trans fluid pressure sensor B circuit.
How serious / can you keep driving: Serious. Power derate likely — plan to stop soon.
Check first: Unplug to invert
Don't risk it — look up listed providers near you and give them this code when you call.
Listed providers nearest Billings, MT
Closest first. Tell them P0846 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 Billings, MT · (406) 245-8985
- 0.0 mi away — based in Billings, MT · (406) 252-8413
- 0.0 mi away — based in Billings, MT · (406) 780-3711
What P0846 means
Trans fluid pressure sensor B circuit. Common causes: Sensor|Wiring.
How serious is it?
Serious. Power derate likely — plan to stop soon.
Most likely causes
- Sensor
- Wiring
First moves (roadside)
- Unplug to invert
FAQ
Trans fluid pressure sensor B circuit. Common causes: Sensor|Wiring.
Serious — Power derate likely — plan to stop soon.
The most common cause is: 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 P0846, or share the same subsystem.
- 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)
- Transmission output shaft speed erratic (SPN 191 FMI 2)
Find a mechanic or related guides
General diagnostic guidance for diesel engines (Cummins, Detroit, PACCAR, Volvo, Mack and more). Not a substitute for a scan-tool diagnosis on your specific truck.