RepairPal Certified shops can diagnose and repair your 1994 Cadillac Seville. They provide transparent pricing with a minimum 12-month or 12,000-mile warranty on repairs and services.
There are a couple of shift sensor valves in the tranny that go. One at a time, so you replace them both. In the lower part of the tranny so not a big job. I got mine done for appx. $350. No problems since. Don't let them talk you into a rebuild. $3,000+