What causes a SPN 48 code?

SPN 48 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 48 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 48 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

J1939 SPN

SPN 48

J1939 SPN 48 — Engine parameter

What it means

J1939 SPN 48 is a generic identifier for an 'Engine Parameter' fault, often signaling that a required message on the J1939 data link is missing, invalid, or out of range.