What causes a SPN 846 code?

SPN 846 can be triggered by several issues — see the verified probable causes and step-by-step diagnostics shared by mechanics and owners on OBDIY.

Can I drive with a SPN 846 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 846 active.

How do I fix SPN 846?

Follow the step-by-step diagnostic on this page, then read the verified fixes contributed by other Heavy Truck owners — the answer marked "Verified Cause" worked for the original poster.

OBDIY

J1939 SPN

SPN 846

J1939 SPN 846 — Engine Management parameter

What it means

Wheel Speed Sensor signal mismatch or data error transmitted over J1939. This parameter is used by the Engine Management System to monitor vehicle speed for cruise control and torque limiting.