Buick Repair Questions? Ask a Mechanic for Answers ASAP
i am assuming the fluid is full ?
when it park will the car NOT roll and be locking on the parking lock ?
if you remove the upper transmission cooler line and put it into an empty 2 litter bottle and start the car up will transmission fluid pour out of the line into the bottle ?
these transmissions by GM and most others are designed to by default have reverse and a forward gear no matter what happens electronically
reverse uses NO electronics to operate as it is a form of a mechanical gear
as for the shift solenoids with 2 solenoids they use to achieve 4 gears with one on and other off ect..in an on and off pattern you can see how you can get 4 gears with 2 solenoids and if power was lost to both solenoids or one of both failed it still would in a configuration to have usually 2nd or 3rd gear
if it flows we know the pump is good and this issue is a torque converter failure or a dreaded failure of the input drum or input clutches along that line
if there is NO flow then the filter is plugged or the pump has failed inside the transmission or the pump drive rod
i know this is not what you wanted to hear but it is honest and the truth and the correct direction to find the issue it will boil down to a transmission issue but which part of the transmission checking for fluid flow will narrow it down to a deep failure or a plugged filter or pump failure or pump drive rod which those 2 are a matter of pulling the bottom pan for the filter and or the side cover to remove the pump and check the pumps drive rod and check the pump vanes to see if they have broken
that tube is the shift TV cable for down shifts when your floor it
the top metal line in the top of the radiator side tube is the line you need to remove
how are you making out ?