ARC Problems..what is this Module???

I have gone through most of my 2000 explorer issues with the Automatic Ride Control system....replaced almost everything...but one thing I don't know is back by the rear switch to engage/disengage this function there is a black box or module with wires running to the switch....everyone I talked to doesn't know what this box is....is this box a part of the ARC system...if so what is its' name? Thanks for any help......I already know where the ARC module is up behind the stereo.....

I asked ebay member automotive_unlimited who has thousands of parts for explorers and he isn't sure either.....no name on box...just a part number

I appreciate any help......