<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Route 66:
What is the purpose of the rocker switch? </div></BLOCKQUOTE>
I'm still studying the Spartan but on an FCCC it served two purposes. First, you can flash out fault codes (if any)by way of the dash lights. Here is link to a page I wrote 6-7 yrs ago for an ISB.
http://www.mydrv.net/how_to_perform.htm
And second, given the proper software on a handheld device you could change engine parameters.