What causes a SPN 697 code?

SPN 697 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 697 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 697 active.

How do I fix SPN 697?

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 697

J1939 SPN 697 — Engine Management parameter

What it means

SPN 697 indicates a fault with the Auxiliary PWM Driver circuit, which controls auxiliary engine functions such as fan clutches, heating elements, or specialized accessories via pulse-width modulation.