Exhaust System, Emission Controls

Secondary Air Injection System

Function

During cold start (+15° to +35° C coolant temperature), air is blown behind exhaust valve by Secondary Air Injection (AIR) system for 65 seconds. This produces an oxygen rich exhaust gas, causes after burning and reduces the heating-up phase of the catalytic converter. Activation is triggered by Engine Control Module (ECM) (J220) via Secondary Air Injection (AIR) pump relay (J299) to Secondary Air Injection (AIR) solenoid valve (N112), (change over valve) and combination valve. In addition, the Secondary Air Injection (AIR) system is switched on with a delay of approximately 20 seconds during idle for 5 seconds after every subsequent engine start (up to max. 85° C engine temperature) and is checked via On Board Diagnostic (OBD).