What causes a SPN 3271 code?

SPN 3271 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 3271 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 3271 active.

How do I fix SPN 3271?

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 3271

SPN 3271: Aftertreatment Exhaust Gas Temperature 4 Sensor Signal Level High

What it means

Indicates the signal voltage from the diesel oxidation catalyst (DOC) or diesel particulate filter (DPF) outlet temperature sensor is above the normal operating range, typically implying an open circuit or sensor failure.