C0031 — Left Front Wheel Speed Sensor Circuit Low
Seen on: Heavy Truck
Left Front Wheel Speed Sensor Circuit Low. Common causes: WSS circuit open or sensor failure.
Your code rides along, so nearby mechanics see the fault before they quote you.
How serious is it?
Serious. Power derate likely — plan to stop soon.
Most likely causes
- WSS circuit open or sensor failure
- Broken tone ring
- wiring damage
- sensor failure
First moves (roadside)
- Inspect LF tone ring
- measure WSS air gap
- test WSS resistance
FAQ
Left Front Wheel Speed Sensor Circuit Low. Common causes: WSS circuit open or sensor failure.
Serious — Power derate likely — plan to stop soon.
The most common cause is: WSS circuit open or sensor failure. Other possibilities include Broken tone ring; wiring damage; sensor failure.
Power derate likely — plan to stop soon. When in doubt, get a qualified mobile diesel tech on the truck before continuing.
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.