Got an '05 XC 90 which has been throwing error messages up intermittently for apparently no good reason. Tells me to check the stop lamps, and they're fine. Tells me the tailgate is open, but it's not. Dome light comes on when these error messages come on. They seem to be triggered by hitting bumps in the road but they also come on when starting the car. Not sure if this is a wiring problem or a switch problem (and I realize they're the same system but they're two separate pieces) and was wondering if anyone had any experience with chasing down this brand of gremlin? Dealer checked the fuses as a "courtesy" but wants $$ to really get in there and maybe diagnose it and I'd much rather DIY this if possible. If anyone can point me in the right direction of where to start looking, it would be greatly appreciated. TIA!