I have a 2002 ss w/ 66000 miles. Had one of the computers replaced 2009 that had something to do with the air conditioning. I have been getting check engine light that stays on(changed gas cap). Also, "info center" located above windshield, does not go on when car is first started up. Until the info center comes on, the fans nor air conditioning will work. I was wondering if anyone has had this problem. Computer related or short? Also, sometimes the car "shifts really hard in 1st and second.
Hate to take to dealer and get charged mega bucks.

 

Sounds like a weak ground

 

Agreed, weak ground or possibly the BCM, but I have no experience with a BCM so maybe someone with a 6th gen and more experience with them will chime in.

The transmission sounds like bad solenoids. Change the fluid and filter and take it from there.

 

Before you go changing the BCM try a new ignition switch. My 2002 SS had the same issues with the DIC and the blower motor for the A/C. I would start my car and the Info center would not turn on nor would the heat or a/c. After a while of driving they would randomly work. My cruise light would sometimes also randomly come on in the dash even though it wasn't turned on. I thought the BCM was bad but I took it to the shop and they said it was the ignition switch. So I replaced it myself and no more issues for over a year now.