Honda Prelude Automatic transmission Computer TCU TCM Up for sale is a Working, in excellent condition 1990-1991 prelude Transmission control unit.  May fit others too.This comes with a 30 day functionality guarantee. In the unlikely event that it fails to function properly in the 30 days after you receive it, you can return it to us and we will send you a free replacement or refund.  Check the part number on your original to be sure this is correct for your car. The part number must match for it to work correctly. A defective TCU can mimic the same symptoms of a defective transmission. Do not erroneously replace a transmission, you will still have the exact same problems if the TCU is defective. Changing this unit only takes about 20 minutes. Try this first!