02 jaguar xj8 sport mode not working

I have an 02 xj8 vanden plas and my sport mode button does not work nor does it light up. Can someone tell me what controls it and potentially a wiring diagram. Thanks

Gus has ALL the wiring diagrams you will ever need on his site, (jagrepair.com)

Has the switch ever worked?
Did someone replace it with a SUPERCHARGED switch? (they are DIFFERENT)