Air Injection Bypass Valve: Description and Operation

Normally Closed AIRB Valves:

PURPOSE
The Secondary Air Injection Bypass (AIRB) valve is used in electronic controlled secondary air injection systems to divert secondary air to the atmosphere during some operating modes.

OPERATION
The AIRB valves are normally closed valves which supply air to the exhaust system with medium and high applied vacuum signals during normal (engine at normal operating temperature) modes. With low or no vacuum applied, the pumped air is dumped through the silencer ports of the valve or through the dump port.