Ok bought the 2000 lesabre with 25k on it...developed hard shifts dealer chgd the epc...problem went away but now with 75k its back..I understand it puts the tranny into hi pressure thats why you hear the pump whine and the hard shifts...if I shut the car off and restart it may not do it again for a month...is there anyway of by passing this epc so it never senses a slow shift and causes this ???
I dont want to have it torn down AGAIN

Change the oil and filter and put in a shift kit. Your days of slow shifts will be behind you.

I was looking for a way to bypass letting the pump go into hi pressure...Like a toggle switch or something...

I dont even think there is a long shift...anyone done the shift kit and then never had the hard shifts or pump going to hi pressure after the kit ??

Which kit is the best one to use and how many qts of fluid and what fluid to use ??
Thx

I believe you 2000 Sabre has 4T65E transmission. Put on in my Pk.Ave easy and no harsh shifts no more. Had the upgraded DEXRON VI (6) with 7 quarts on standby. Put in 6 drove til hot then topped up until on full line. Also I use LubeGard red bottle to keep fluid cool.
Here is a link to shift kit I used
TransGo | 4T65E: SK 4T65E
Before I did the shift kit install, I used Trans Tune Can to clean up any varnish especially towards the valve body end.
Trans Tune | Sea Foam Sales Company
You drop tranny pan and drop down accumulator to install shift kit. Transgo has good instructions and my photos from this page will then make sense, how stuff laid out on table etc.
https://www.gmforum.com/buick-172/4t...-302566/page5/
Hope that helps.