What causes a SPN 523602 code?

SPN 523602 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 523602 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 523602 active.

How do I fix SPN 523602?

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 523602

Transmission Control Module (TCM) Internal Fault

What it means

This code indicates an internal fault within the Transmission Control Module itself. The likely root cause is a hardware or software malfunction within the TCM.