Lumina V6-204 3.4L DOHC (1991)
Air Injection Reaction (AIR) System: Description and Operation
SYSTEM DESCRIPTION
This system is used to reduce Carbon Monoxide (CO) and Hydrocarbon (HC) emissions. It also heats up the catalytic converter quickly, on engine
start-up, so the conversion of exhaust gases will occur sooner.
The A.I.R. system includes:
1.
An Electric Air Pump:
A computer controlled electric air pump provides air for the system during open loop operation only, for a maximum time of 80 seconds.
2.
Control Valve (EDV):
The control valve directs the flow of air from the electric air pump to the exhaust ports or to the atmosphere.
3.
Control (EDV) Solenoid:
The Electric Divert Valve Solenoid is normally closed and controls vacuum to an internal valve which performs a switching operation by direction
air flow from the electric air pump to the exhaust ports (solenoid energized) or to the atmosphere (solenoid de-energized). The ECM provides the
ground to complete the circuit and energize the EDV solenoid. The electric air pump relay and Electric Divert Valve solenoid are energized
simultaneously by the ECM.
4.
Check Valves:
The check valves prevent back flow of exhaust into the pump in the event of an exhaust backfire.
5.
Necessary plumbing.
CAUTION: Mask off the inlet air silencer whenever pressure washing or steam cleaning the engine compartment to prevent damage to the air pump.
ELECTRIC DIVERT VALVE DESCRIPTION
The electric air pump operation and EDV solenoid are controlled by the ECM. The ECM will turn on the electric air pump by providing the ground to
energize the air pump relay. The EDV solenoid is also energized when the ECM provides the ground.
When air to the exhaust ports is desired, the ECM turns on both the electric air pump and the EDV solenoid.
