Diagnostic Aids
WARNING: This page is about a different car, the 2010 GMC Sierra, 2010 GMC Cab & Chassis Sierra, 2010 Chevrolet Silverado, and 2010 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
Inspect the ISS/OSS, harness, connector, and control solenoid valve assembly for metallic debris and the 1-2-3-4 and 3-5-R clutch housing splines on the outside diameter surface for damage or misalignment. Proper torque of the ISS/OSS mounting bolt is critical to proper speed signal operation.