Theory Of Operation
WARNING: This page is about a different car, the 2013 RAM 3500 HD and 2013 RAM 2500 HD. However, it is still accessible from the selected car via links, so may be relevant.
This monitor can detect a severe restriction in the Air Filter or the inlet hose to the Airbox. This can cause a reduction in air flow large enough to cause damage to other engine components. This will cause the fault to be set. When this DTC is active, EGR flow is disabled.