What causes a SPN 3071 code?

SPN 3071 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 3071 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 3071 active.

How do I fix SPN 3071?

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 3071

SPN 3071 Aftertreatment System Main Power Relay

What it means

This fault indicates the Engine Control Module (ECM) has detected an improper voltage or internal circuit failure in the Aftertreatment Main Power Relay.