What causes a SPN 2709 code?

SPN 2709 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 2709 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 2709 active.

How do I fix SPN 2709?

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 2709

J1939 SPN 2709 — Aftertreatment/Emissions parameter

What it means

The SPN 2709 code usually relates to Aftertreatment SCR Catalyst Efficiency or Temperature Performance. It indicates the ECM has detected that the SCR system is not reaching or maintaining the required operating temperature or efficiency to reduce NOx.