Diagnostic Aids
WARNING: This page is about a different car, the 2002 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
To locate an intermittent problem, monitor PNP switch A/B/C/P while moving the related connectors and wiring harness. If a malfunction occurs, the scan data will change states from HI to LOW or from LOW to HI. Move the gearshift lever slowly through each gear position while monitoring the scan tool to help isolate the problem.