Theory Of Operation
WARNING: This page is about a different car, the 2013 Dodge Avenger and 2013 Chrysler 200. However, it is still accessible from the selected car via links, so may be relevant.
The Secondary Air Injection System reduces hydrocarbon emissions by decreasing the catalyst warm up time. During a cold engine start, after a short diagnostic time out, typically two to three seconds, the Powertrain Control Module (PCM) commands the Secondary Air Pump on for approximately 20 seconds. The Secondary Air Pump supplies air to the exhaust manifold through the Secondary Air Pump Valve, a one-way check valve. This additional air introduced to the exhaust flow aids in the warm up of the catalyst.