Air Injection: Description and Operation

PURPOSE

The purpose of the Secondary Air Injection (AIR) System is to reduce exhaust emissions during engine warm up when the engine management system is in open loop.

OPERATION

The AIR System injects a calibrated amount of air behind the exhaust valves for 65 seconds during a cold start when the engine coolant temperature is between 15C and 35C (58F and 95F).
The additional air provided by the pump in to the exhaust initiates after-burning.
This enables the catalytic converter to reduce exhaust emissions during the engine warm up phase even though the Motronic engine management system is in open loop.

In addition, each time the engine is started again after the initial start and remains at idle, the AIR system is switched on after a 20 second delay for 5 seconds. Until the engine coolant reaches 85C (185F)

The AIR system is monitored by the On Board Diagnostic system.

COMPONENTS

Electric Air Injection Pump.

Air Control Solenoid.

Air Injection Check Valve.

Air Injection Pump Relay.

30amp Fuse for Air Injection Pump