Well the only way I know how is when the 4wd light goes on, pop the trunk and stick your noggin into the boot and look up to the parcel shelf, the silverish box on the left, should have a sight glass so to speak, which will be flashing codes out with an led. count the dots, it will leave a space between errors, and will cycle through after its done, just make sure not to check it in a confined space, exhaust fumes ftl lol Not sure if it throws up the errors as well, if you just pull out the fuse.
Like the other guy in this thread, my g sensor line is still white, not red, so I'm a bit lost as to what to do, the only small clue I have is that yesterday, the 4wd light decided to come on when I was braking hard, and it then through up the g sensor code, so I thought perhaps it's a wiring issue?
any helps much appreciated.