2007 Buick LaCrosse Tranmission shifts hard after stop.

jack1964

I have a 2007 Buick Lacrosse.3.8, during normal driving the trans will be working fine, but out of the blue .If I stop at a stop light or stop sign.And then take off and it will shift hard for no reason. but if I pull over and shut the car off and let it sit for atleast 2 minutes and start it up and take off it will shift fine. It don't do it all the time, but it will do it again maybe two days later. or sometimes it may go a month with out it happening again.any ideas.

cmhj2000

Miles? Maintenance history on trany?

jack1964

155.000 miles on trans, no other problems at all, I think its a bad electrical part , because if I shut the car off, and restart. it goes away.