I just had a similar case on a 2008 CTS this afternoon. I performed the door latch freezing campaign modification on this vehicle a few weeks ago, and not sure if it had something to do with the failure. There are screws that hold the panel on, two are under the trim piece that makes up part of the door pull handle, and 1 is behind the trim plate inside of the inside door handle. You may not need to remove the panel, though. Ultimately, after I removed the panel and checked for signal to the latch, I was setting up to try reprogramming the drivers door module. I was needing to get a supplemental battery charger, and thought while I was doing that, I would disconnect the battery cables and short them together. This is a means of discharging the capacitors, and removing all power and memory from individual modules on a grand scale. After reconnecting them, I first decided to try a function test and the system worked as designed. I suspected after that, it may have been some form of logic lock of the door module. So to keep it simple at first, I would try disconnecting the battery cables(both), and connecting a jumper wire between them, or touch them together for a minute or so. It didn't seem as though there was provision in the cables to get them together, so I reached for a jumper wire, I didn't try very hard though. Then check the operation, and if it returns to normal, let me know, it may be useful on future concerns. If it doesn't return, let me know as well.
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Saturday, October 16th, 2010 AT 1:54 AM