Compressor Head Relief
WARNING: This page is about a different car, the 2003 Pontiac Montana, 2003 Oldsmobile Silhouette, and 2003 Chevrolet Venture. However, it is still accessible from the selected car via links, so may be relevant.
A 1.5 second actuation of the exhaust solenoid valve occurs each time the compressor is to start to ensure the low compressor motor starting current. The 1.5 second actuation of the exhaust solenoid valve reduces the air pressure in the compressor head cavity.