Secondary air system: Function
WARNING: This page is about a different car, the 2006 Audi A4, 2005 Audi A4, 2004 Audi A4, 2003 Audi A4, and 2002 Audi A4. However, it is still accessible from the selected car via links, so may be relevant.
- In the cold start phase, the ECM -6- activates the secondary air pump -1- via the relay for secondary air pump -5-. Air reaches the combination valve for Secondary Air Injection (AIR) system -3-.
- The Secondary Air Injection (AIR) valve -8- is activated in parallel, which allows the vacuum to reach the combination valve for Secondary Air Injection (AIR) -3-. The combination valve for Secondary Air Injection (AIR) thereby opens the path for secondary air to the exhaust channels of the cylinder head.