J1939 SPN
SPN 3742

J1939 SPN 3742 — Body/Chassis parameter

What it means

SPN 3742 indicates a generic or specific Body/Chassis parameter fault. This often relates to auxiliary equipment logic (like PTO, outriggers, or bed position) not matching the chassis expectations or a communication break between the Body Control Module (BCM) and the engine/chassis network.

Sign in to view symptoms, probable causes, diagnostic steps, severity, and related codes