pcm is the last resort-check the sensers and the torque converter first. check the tcc with the drb3 theere is a tcc test in it for this trans. If the motor stalls during the test it passes. Look for debris in the pan when dropped. What you are looking for is brown ***** of converter clutch. looks like little ***** of clay-llike 1st and 2nd graders play with. if ok then replace the govener pressure senser and --repeat and the governer pressure transducer. These two work together and one will supply the wrong info to the other. cost is about 200 dollars. Sometime you can find these aftermarket--not everyone has them. they install externally on the valve body and can be changed w/o dropping the valvebody. The other stuff requires dropping and
overhaulling the trans.