Vehicle Speed Sensitive Wipers
WARNING: This page is about a different car, the 2010 Pontiac G5 and 2010 Chevrolet Cobalt. However, it is still accessible from the selected car via links, so may be relevant.
When the wipers are placed in any of the INT positions, the BCM will decrease the wiper delay as vehicle speed increases in order to keep windshield visibility clear. The BCM receives vehicle speed via class 2 from the ECM.