GM Service Manual Online
For 1990-2009 cars only

Intelligent Switching Unit (ISU)

Wiper Park Switch: The scan tool displays Active or Inactive. When the wipers are parked, the scan tool will display Active. When the wipers are operating, the scan tool will display Inactive.

Wiper Switch: The scan tool displays OFF, Delay or ON. When the switch is turned to the INT position from OFF, the scan tool displays Delay. When the windshield wiper/washer switch is turned to the wash, low, or high positions the scan tool displays ON. Anytime the switch is in the off position the scan tool displays OFF.

Wiper Washer Switch: The scan tool displays Active or Inactive. When the washer switch is engaged, the scan tool will display Active. When the switch is disengaged, the scan tool will display Inactive.