What you probably have is a parasitic drain. Patty2013: The term is a “short circuit”, not shortage. I hope the dealer mechanics are bright enough to diagnose the problem properly and not just toss parts at it.
So long story short, the cluster may not even be the root of the problem. I know the system is supposed to realize if you’ve left interior lights on or the door open and shut them down after some time to preserve the battery (according to the manual), but who knows–if a sensor like a door switch was far enough out of adjustment that it kept randomly sending a signal to the system and kept waking everything up, instead of a steady “on” like would happen if you just left the door open, I could see how the battery would be run down by it–the timer would be reset every time the module got a pulse from the malfunctioning switch and wake up again. I would assume that it’s bright enough to go to sleep before the battery would be drained, but I’ve never tested it. On my car if you open a door or pop the trunk, the cluster wakes up to display the door ajar or other warning message. The cluster, while the source of the parasitic drain, may not even be at fault if there is a sensor or other module that is not letting it sleep or keeps waking it up. If the module that manages the cluster isn’t going to sleep when it’s supposed to, it can certainly drain the battery.
I guess my point is that the cluster on a modern vehicle is a lot more complex than the panels of yesteryear that just served to hold the speedometer and other instruments. A modern vehicle can have a dozen or more “computers” of varying complexity, all of which talk to each other, typically through a gateway, which is just a module that does extra duty and manages these communications, similar in a way to the router in your home that allows computers and other networked devices to talk to each other and the Internet.īut that’s getting off track. I think some GMs have the radio as the controller.
On some vehicles the cluster is the “gateway” or controller for the network, on some the “BCM” or Body Controller Module is. The cluster contains a computer that is networked with the other computers in the vehicle.