21st May 2012, 19:15
It is the BCM (Body Control Module). I have found that there is a faulty solder joint inside the BCM that tends to heat up, and the contact becomes compromised. I resoldered the joint and mine works fine now. The hard part is getting the BCM out, as it is buried deep in the center console.
12th Jun 2011, 19:38
I have the same issue with my 2000 Denali. It is caused by corrosion, and or a bad soldering connection on the circuit board of the BCM "Body Control Module". It is located under the center console. I found this because the problem started when changing CDs in the changer, located in the console. When I slam the console door everything works for a while. Sometimes having a temper is good.