It's a '94 540i with the ZF5HP30 transmission. First reverse went out, which I learned is a transmission defect corrected with a mod kit in the valve body ($39.95). But when opened I also needed an AC Drum Pack, converter, and cooler. After $1700 in parts from ZF the trans program kicks in and I'm stuck in 3rd gear, reverse is now fine. Replacing the speed sensors after having received this code in test has not solved the problem. ZF has a trouble shooting guide but cannot release it due to it's contractual relationship with BMW. They want to replace the unit for $5000. Any help out there?