Checking power supply
WARNING: This page is about a different car, the 2006 Audi A4, 2005 Audi A4, 2004 Audi A4, and 2003 Audi A4. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
- Secondary Air Injection (AIR) solenoid valve N112 is supplied with power via fuel pump relay.