Version 2

Principle and Function

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

Principle

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.

Function

• In the cold start phase, the engine control module controls the Secondary Air Injection (AIR) pump via the pump relay. Air reach secondary air injection combi-valves.

• The secondary air injection solenoid valve is activated in parallel which allows the vacuum to reach the secondary air injection combi-valves. The appropriate combination valve for Secondary Air Injection (AIR) thereby opens the path for secondary air to the exhaust channels of the cylinder head.