What causes a SPN 1439 code?

SPN 1439 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 1439 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 1439 active.

How do I fix SPN 1439?

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.

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J1939 SPN

SPN 1439

DPF Intake Pressure (Bank 1) Calibration Error

What it means

The ECM has detected the DPF intake pressure sensor is out of calibration or not zeroing correctly.

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