Air Injection Pump: Description and Operation

The mechanical rotary vane air pump is belt driven through an electromagnetic clutch. The clutch allows the pump to be engaged/disengaged by the ECM (via the air injection relay. If the engine speed exceeds 2500 rpm while air injection is enabled, the ECM will switch OFF the circuit to prevent over speeding the air pump. Excessive back pressure would damage the pump.

Air Pump: