GM has designed in a lot of tricks to cost you money and one of the most common is from disconnecting the battery, ... However, that should not apply yet to a 2002 model. Look for blown fuses. Very often they blow from the surge of computer memory circuits charging up when the battery is reconnected. There is no other problem, and replacing the blown fuse(s) is all that's needed.
In general, the newer the vehicle, the more likely you will end up with a towing bill and very expensive repairs from simply disconnecting the battery to replace it or from letting it run dead. Only Volkswagen is more customer-unfriendly than General Motors in this regard, but it's becoming a problem will all brands of cars. The problem isn't blown fuses; it's computers that lock up and have to be unlocked or have the software reinstalled by the dealer over their internet connection. Toyota and Chrysler allow any independent shop access to their web sites for a small fee to update software. Only Hyundai allows anyone total access to their web site 100 percent for free. GM locks up all of their information and refuses to release anything to independent shops except for three computers as mandated by the government because they affect emissions. That leaves the dealer's expensive service department as your only choice for the other up to 44 computers.
A safer choice is to never ever disconnect the battery, and if you have to replace it, use a "memory saver" that plugs into the cigarette lighter. I always use a small battery charger to maintain the computers' memories while the battery is being replaced. That always works. Memory savers only work with cigarette lighter outlets that remain live with the ignition switch off.
Monday, December 26th, 2011 AT 9:34 PM