Transmission problem
2004 Buick Rendezvous 6 cyl All Wheel Drive Automatic 82000 miles
----------------------------------------------------------------
Sirs,

Recently after a long drive (over 100 miles) my transmission shifted very rough (noticable clunk). I took it to a reputable transmission shop and changed the fluid and filter. They also said my transmission showed code #1811. Since then it occasionally skips or hesitates when accelerating ( about every third time). Any ideas other than replacement?

Sounds like it's time to rebuild it. It probably has a bad input clutch piston and piston seal.

I am a GM/ASE Certified Trans Tech, with 12+ years experience. Your P1811 Code is for the Trans Pressure control Soleniod, which controls the transmisson line pressure. when the code sets, it commands line pressure to max, and also sets all the transmisson shift adapts to max therefore givng you the harsh and delayed shifting. with only 82000 on your vehicle, I would recommend having a new soleniod installed, usually around a $700 repair at most GM dealerships, once the repair is done, and the transmisson adapts are reset, and code is cleared, you should be as good as new again

With 82,000 miles , it would be a wise investment to spend 2,500 for an overhaul rather than 700-1,000 on a solenoid.