Cummins 4239 Aftertreatment 1 SCR Dosing Air Assist Absolute Pressure - Data Valid But Above Normal Operating Range - Moderately Severe
What this code means
Cummins fault code 4239 (SPN 4335 / FMI 0) refers to: Aftertreatment 1 SCR Dosing Air Assist Absolute Pressure - Data Valid But Above Normal Operating Range - Moderately Severe. It is logged by the engine control module (ECM) on Cummins-powered vehicles and read over the J1939 diagnostic network.
Emissions system
This is an emissions after-treatment related fault on the SCR & DEF system. On Cummins-powered vehicles it is commonly seen when that after-treatment system is faulty, restricted, or has been modified.
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Frequently asked questions
Cummins fault code 4239 (SPN 4335 / FMI 0) indicates aftertreatment 1 scr dosing air assist absolute pressure - data valid but above normal operating range - moderately severe.
Cummins 4239 is generally treated as a serious fault. Have the engine and its wiring inspected, and confirm the reading with a J1939 diagnostic scan before clearing the code.
Yes. Cummins 4239 is associated with the SCR & DEF after-treatment system on Cummins engines.
