Automatic Transmission problems of the 2000 Chevrolet Lumina

I have a 2000 chevy Lumina with 54,xxx miles on it. In 2003 when it had 22,xxx miles on it I had the transmission worked on because it was shuttering and shifting hard. It was still under warranty at the time. Now, 6 years later I am having the exact same problem and am told I have to have a whole new transmission installed. A car that has 54,xxx miles on it and has always been serviced on time should not have the transmission go out. It had a code of 1810 when diagnostics was done to it.

Had to change battery, this causes the on board computer to reset to original setting. The transmission (4t65e) is programmed to make shifts at certain speeds in an allotted time span. Because now, the car (2000 Lumina) is older and the shifts are a little longer the computer sends messages to the transmission to force pressure on the lines to correct split second shifting. This causes hard shifting and grinding sounds. I stop the car, turn the motor off, then on and its ok again for a few more miles. A transmission shop wants $1400. 00 to fix problem, but the problem is a not so Smart computer that doesn't allow for a car to age.

When driving from first to second gear vehicle would surge and from second to third it would resurge. Dealer notified, and was unable to locate cause. Feel free to provide any further information concerning this matter.