Air Injection: Description and Operation

Secondary Air Injection System Function

• Due to the rich mixture during the cold start phase, the exhaust emissions contain an increased level of unburned hydrocarbons. The Secondary Air Injection (AIR) system improves the secondary oxidation within the catalytic converter, thereby reducing harmful emissions. The heat released by secondary oxidation shortens the start up time of the catalytic converter considerably, as well as significantly improves emissions quality during the cold-running phase.

• The Secondary Air Injection (AIR) pump relay (J299) , Secondary Air Injection (AIR) solenoid valve (N112) and Secondary Air Injection (AIR) solenoid valve 2 (N320) are activated via the Engine Control Module (ECM) (J623).