2007 LACROSSE all guages are out

I have a 2007 Buick Lacrosse CXS with 58000 miles. Today all of the guages went out. No tach, speedometer, gas gauge, temp gauge, the traction control light is on and the automatic door locks do not work. The Odometer and compass also do not work.
Any ideas what would be the cause or this.
I read online that GM has extended the warranty for this problem but the list of cars did not include the Lacrosse but did include the Impala.

Thanks for any help with this problem

First place to start would be to read P, B, and U codes, and to see if you can communicate with ALL modules......but that would take an expensive scan tool like a Tech II....

Thanks tech II that is where I will start. I didn't know a scan would tell me anything like that.

Could it be a bad ground wire/connection? I had an old buick skylark 1980's. The car would run but all extra electrical would not work.

I thought of the bad ground so I cleaned the battery posts but I did nothing elese caught my eye

Well took the car to my mechanic and he checked the codes for P,B & U codes and he said he got tired of writing them down. He told me only a dealer would be able to correct the problem and he believes it wiil require a new or reprogrammed computer.
Dropped it off at the at the dealer, may not hear from them until next week.

Well my car was at the dealer for over two weeks. When I called them to inquire on the status they told me they would call me back but I never rec'd the call. I went to the dealer and they told me they replaced the BCM at a cost of $618 and that only cleared one code and all the rest of the codes still showed. One day later they called to tell me the car was fixed that they also replaced the PCM and that corrected the problem. That computer was covered under warranty.
I have a feeling I may have been screwed and that the BCM did not have to be replaced.

How was the pcm still covered under warranty?? Was it replaced before this? 2007 is a long time to warranty a car.