Passive and Active Diagnostic Tests
WARNING: This page is about a different car, the 2008 Suzuki Reno, 2008 Suzuki Forenza, 2007 Suzuki Reno, and 2007 Suzuki Forenza. However, it is still accessible from the selected car via links, so may be relevant.
A passive test is a diagnostic test which simply monitors a vehicle system or component. Conversely, an active test, actually takes some sort of action when performing diagnostic functions, often in response to a failed passive test. For example, the Exhaust Gas Recirculation (EGR) diagnostic active test will force the EGR valve open during closed throttle deceleration and/or force the EGR valve closed during a steady state. Either action should result in a change in manifold pressure.