Volvo All Engines (2010 Emissions) Fault Code: SPN 3491 FMI 12 PID: Aftertreatment DPF Atomization Air Actuator

The atomization air valve is part of the atomization module and the combustion air valve is located on the engine. Both are controlled by the same DPF ECU output. The valves are normally closed and are opened when voltage is supplied by the DPF ECU. When opened, compressed air supplied from the air tank through the priority valve is supplied through the atomization air valve to the atomization nozzle while charged air from the intake manifold is supplied through the combustion air valve to the DPF Unit combustion chamber.

Observable symptoms
1) Regeneration not possible

Probable cause
1) Aftertreatment Diesel Particulate Filter (DPF) Atomization Module (Aftertreatment DPF Atomization Air Actuator)