Work sequence

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:

The Secondary Air Injection (AIR) solenoid valve N112 and its wiring are monitored by the engine control module.

Read DTC memory of engine control module.

If display shows a DTC relating to secondary Air Injection (AIR) solenoid valve N112 :

Fig 1: Identifying Secondary Air Injection (AIR) Solenoid Valve -N112-

Courtesy of VOLKSWAGEN UNITED STATES, INC.

Disconnect hoses from secondary Air Injection (AIR) solenoid valve N112 - 2 - , but leave electrical connector connected.

Installation location: under intake manifold

NOTE:

Illustration shows removed intake manifold viewed from below.

Fig 2: Connect Test Hose To Valve Connection

Courtesy of VOLKSWAGEN UNITED STATES, INC.

Connect test hose to valve connection marked with an - arrow -.
Start output Diagnostic Test Mode and actuate Secondary Air Injection (AIR) solenoid valve N112.

Indicated on display

Output Diagnostic Test Mode →
Secondary Air Injection solenoid valve -N112

Valve must click...
..and must open and close (can be checked by blowing into test hose).

If valve does not click:

Check internal resistance of valve.

If valve does not open or close properly:

Replace Secondary Air Injection (AIR) solenoid valve N112.