What causes a SPN 3433 code?

SPN 3433 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 3433 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 3433 active.

How do I fix SPN 3433?

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 3433

J1939 SPN 3433 — Body/Chassis parameter

What it means

SPN 3433 refers to the Aftertreatment System 1 SCR Catalyst Intake Gas Sensor Intake Power Supply. It indicates a voltage out of range or a communication error related to the body/chassis interface regarding exhaust configuration.