Diagnostic Aids
WARNING: This page is about a different car, the 2008 Buick LaCrosse and 2008 Buick Allure. However, it is still accessible from the selected car via links, so may be relevant.
Inspect the ISS, wire harness, connector, and TCM for metallic debris, damage, or misalignment. Ensure the wiring harness is not stretched too tightly or other components are pressing on the automatic transmission inline 20-way connector body. Also inspect for proper clearance to any other components and wiring.