Pump, Air: Operation: Operation

The powertrain control module (PCM) controls air pump operation through the air pump relay. During cold start, air is drawn into the air injector pump through a tube that is connected to the mass air flow (MAF) sensor.

The air is then compressed by the pump and expelled into the connecting tube where it reaches the one way check valve. The one way check valve protects the connecting tube and air pump from hot exhaust gases backing up into the system.