Secondary Air Injection (AIR) system: Function

WARNING: This page does not describe the selected car, but rather 14 other vehicles, including the 2005 Volkswagen GTI, 2004 Volkswagen R32, 2004 Volkswagen Jetta, 2004 Volkswagen GTI, and 2003 Volkswagen Jetta. However, it is still accessible from the selected car via links, so may be relevant.

Air is blown behind the exhaust valves by the Secondary Air Injection (AIR) system during a cold start. Thereby, the emission gas is enriched with oxygen, initiating a secondary combustion and thereby shortening the warm-up phase of the catalytic converter. Activation occurs from Motronic Engine Control Module (ECM) -J220- via Secondary Air Injection (AIR) Pump Relay -J299- to Secondary Air Injection (AIR) Solenoid Valve -N112- to the combination valve.

NOTE:

Always replace seals and gaskets.
Vacuum lines and hose connections must not have leaks.
Vacuum hoses must not be clogged or kinked.
For the electric components to work properly, a voltage of at least 11.5 V is required.
Engine Control Module (ECM) is equipped with On Board Diagnostic (OBD).
Components marked with * are tested via On Board Diagnostic (OBD). Refer to Diagnostic mode 3: Check DTC Memory
It is possible that the control module will recognize a malfunction and store a DTC during some tests. Therefore the following work steps must be performed in the mentioned sequence after ending all tests and repairs.

Check DTC memory. Refer to Diagnostic mode 3: Check DTC Memory
Erase DTC memory. Refer to Diagnostic mode 4: Reset/erase diagnostic data
For completion, generate readiness code. Refer to Readiness code, generating

Secondary Air Injection (AIR) system components, removing and installing:

Vehicles with engine code AFP. Refer to Parts of Secondary Air Injection (AIR) system (vehicles with engine code AFP), removing and installing ,
Vehicles with engine code BDF. Refer to Parts of Secondary Air Injection (AIR) system (vehicles with engine code BDF), removing and installing ,
Vehicles with engine code BJS. Refer to Parts of Secondary Air Injection (AIR) system (vehicles with engine code BJS), removing and installing .

Check secondary air system for proper seal. Refer to Secondary Air Injection (AIR) system, checking for proper seal .