Erratic Shifting of the Automatic Transmission on Pontiac Bonneville

Problem Description and Possible Solution

The transmission pressure control solenoid may fail causing erratic shifting. Our technicians tell us that partial dis-assembly of the transmission is necessary to replace a failed pressure control solenoid.

Problem Data
RepairPal Verified
Average mileage: 145,186 (16,000–354,000)
10 model years affected: 1993, 1996, 1997, 1998, more1999, 2000, 2001, 2002, 2003, 2004
56 people reported this problem
Viewing 1 - 18 of 18 comments
My car does not shift into gear very well. Computer reading shows problems with solenoid. I actually have 2-Pontiac Bonneville's ('02 SSEI & '03) that are experiencing the same problem. The 2002 SSEI has worse shifting problems than the 2003, however, they are both experiencing similar shifting problems.

Nice cars but faulty shifting problems. I need to fix them....
After about 20-30 minutes of driving the transmission will shift slightly harder than normal. Any ideas on how to fix this problem?
after the car is driven for about 30 minutes, especially in warm weather, it will start to have hard up-shifts only.
My drive and third gear is gone only thing moving is my RPM's, if i put it 2nd gear and get up to 25mph i can shift to drive and it will pick up
when i drive it it shifts hard from takeing off from 1 to 3 and when it down shifts it trys to kill the moter whats wrong with my car ?
When warm from a standing stop the transmission will shudder under hard acceleration . Also up shifts become erratic and very harsh. Solution, Replace the pressure control solenoid.(If your not a decent wrench spinner take it to a shop)
car acts if it is lunging or misfiring at various speeds , to test just litely touch brake and see if it goes away while lunging if it does its the control solenoid in tranny
When the when it starts in the morning it won't move and it's full of fluid and it shifts really hard in to get slammed
I recently changed the transmission due to a drive band breaking, the new trans would shift good till it got warm then it would shift hard n slip shifting into 2nd gear.
Problem moving to third and fourth gear, slows down in third and fourth gear, however no problem in 2nd or 1st gear.
I have to leave it in neutral and let it warm up Before it will Try to shift into gear Then it shifts hard going down the road.