Why wont trans shift into 2nd gear

Hello, Dave here, contributing to RepairPal and providing expert advice since 2010. The 5R55E and 5R55S transmissions used in these vehicles were known to have valve body / servo issues. A stuck check valve causes problems in some cases. Being that this vehicle is 21 years old with who knows how many miles -- it's really hard too know what's going on. One thing for sure is that your concern is almost surely due to an internal mechanical transmission concern that will likely result in needed replacement. First, it would be prudent to have diagnostic testing performed to learn what trouble codes might be set in the engines processor related to transmission performance. Those clues could help lead you to a point of understanding what is actually happening so that a good decision for repair can be made. If you need help with this, reach out to a local shop near you! https://repairpal.com/auto-repair-near-me Click the link or call us at 877-913-1554. We'll gladly find you a certified RepairPal shop in your area.