What causes a SPN 3240 code?

SPN 3240 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 3240 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 3240 active.

How do I fix SPN 3240?

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 3240

Exhaust Gas Temperature Bank 1 Sensor 1 Circuit Fault

What it means

The Engine Control Module (ECM) detects an out-of-range voltage or signal interruption from the Exhaust Gas Temperature (EGT) sensor located at the inlet of the Diesel Particulate Filter (DPF).