What causes a SPN 3105 code?

SPN 3105 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 3105 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 3105 active.

How do I fix SPN 3105?

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 3105

J1939 SPN 3105 — Body/Chassis parameter

What it means

J1939 Network Error - Body/Chassis Parameter Data. This code indicates the ECM is receiving invalid or missing data regarding a specific chassis-related parameter (such as PTO status, park brake, or neutral switch) over the J1939 data link.