What causes a SPN 7133 code?

SPN 7133 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 7133 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 7133 active.

How do I fix SPN 7133?

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 7133

Cummins fault code 7133

What it means

Aftertreatment 1 Diesel Exhaust Fluid Quality - Abnormal Update Rate. This code indicates the Engine Control Module (ECM) is receiving invalid or missing data regarding the DEF quality/concentration.