What causes a SPN 5323 code?

SPN 5323 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 5323 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 5323 active.

How do I fix SPN 5323?

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 5323

Excessive Time to Enter Closed Loop Fuel Pressure Control

What it means

The ECM has detected that the fuel system took too long to transition from open-loop (startup/prime) to closed-loop (regulated) pressure control.