Torque Converter Clutch (TCC) Intermittent - OK Cold/Slips Hot
WARNING: This page is about a different car, the 2003 GMC Safari and 2003 Chevrolet Astro. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Torque Converter Clutch Intermittent - OK Cold/Slips Hot