What causes a SPN 1 code?

SPN 1 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 1 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 1 active.

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

Log in Sign up

J1939 SPN

SPN 1

N/A - General Sensor Signal

What it means

General suspect parameter number often associated with a wheel speed sensor or invalid sensor data depending on proprietary FMI.

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

Log in Sign up free