Secondary Air Injection System

Secondary Air Injection System

• The Secondary Air Injection (AIR) system heats up the engine faster, and thereby the catalytic converter achieves operation readiness earlier after a cold start.

• Due to the rich mixture during the cold start phase, the exhaust emissions contain an increased level of unburned hydrocarbons. The 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.

Function

• In the cold start phase, the ECM - 6 - activates the secondary air pump - 1 - via the relay for the secondary air injection - 5 -. Air reaches the secondary air combi-valve - 3 -.

• At the same time, the secondary air valve - 8 - is activated, the vacuum reaches the secondary air combi-valve - 3 -. The combination valve for AIR thereby opens the path for secondary air to the exhaust channels of the cylinder head.