Air Injection: Description and Operation

Secondary Air Injection (AIR) System

WARNING: Observe the following for all installations, especially in engine compartment due to lack of room:
- Route lines of all types (e.g. for fuel, hydraulic, EVAP canister system, coolant and refrigerant, brake fluid, vacuum) and electrical wiring so that the original path is followed.
- Watch for sufficient clearance to all moving or hot components.

Function
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 combination valve.

Secondary Air Injection (AIR) system components, removing and installing:
- Vehicles with engine code AEG, AVH, AZG.
- Vehicles with engine code BDC.

Check secondary air system for proper seal.