Secondary Air Injection (AIR) system: Function

WARNING: This page is about a different variant/trim than selected.

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 .