I was going over some maintenance items that I want to do to the 02 XJR and I came across some downloads regarding the BPS. I had downloaded a bunch of information after I had a single "restricted performance" problem one night many months ago.

This is from TB 206-07 Dated 04/02: It recommends replacing BPS with the updated switch if the car came with the original style -- that is obviously the way it normally works. But it recommends that you replace both the switch and the pedal (Cost of that!) if you already have the new style switch installed.

Why is that the case?