BCM 2000 Olds Silhouette

[Beachghost]

Does anyone have any tips on how to verify that your BCM is toast, apart from the dealer hooking it up to there scanner for 3 or 4 hours at over 80 dollars an hour.
My garage checked everything like fuses and breakers and went as far as they could with their generic scanner.
if I purchase a BCM from the dealer at 250 cdn dollars, then I can't return it.

The symtoms are: I have lost all power to windows door locks remote operener, internal dome light. I have to do everthing manually. I can drive the vechicle no problem even with BCM removed.