Air Injection: Description and Operation

Secondary air system

CAUTION:
When performing repair work, especially due to the confined conditions in the engine compartment, pay attention to the following:
^ Route all types of lines (e.g. for fuel, hydraulics, EVAP system, coolant, refrigerant, brake fluid and vacuum) as well as electrical wiring so that the original positions are restored.
^ Ensure sufficient clearance to all moving or hot components.

Function
During cold starting the secondary air system blows air in behind the exhaust valves. This produces an oxygen rich exhaust gas, causes after burning and reduces the heating-up phase of the catalytic converter. Activation is performed by the Motronic Engine Control Module -J220via the Secondary Air Injection (AIR) pump relay -J299- to the combi-valve.
Checking secondary air system, Refer to Air Injection, Testing and Inspection