Additional Information, Functional Description

Functional Description

The secondary air system blows air in behind the exhaust valves for a maximum 100 seconds following a cold start (+5 degrees C to +33 degrees C coolant temperature). This produces an oxygen rich exhaust gas, causing after burning and reducing the heat-up phase of the catalytic converter.

The activation is performed by:
- The Motronic Engine Control Module (ECM) -J220- via the Secondary Air Injection (AIR) pump relay -J299- to the Secondary Air Injection (AIR) solenoid valve -N112- (intake manifold) and the combination valve, in engine code AEG up to 05.99.
- The Motronic Engine Control Module (ECM) -J220- via the Secondary Air Injection (AIR) pump relay -J299- to the combination valve, in engine codes AVH, AZG, BDC, BEV, BGD and AEG from 06.99.

Additionally after each subsequent engine start (up to max. 96 degrees C engine temperature) the secondary air system will switch in for 10 seconds during idling and will be checked by the On Board Diagnostic (OBD). The oxygen sensor regulation must then be active.