What causes a SPN 3234 code?

SPN 3234 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 3234 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 3234 active.

How do I fix SPN 3234?

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 3234

SPN 3234 - Exhaust Gas Oxygen Sensor 1 Heater Current Abnormal

What it means

This code indicates that the engine control module has detected an electrical fault or out-of-range current within the heating element circuit of the intake/upstream wideband NOx or O2 sensor.