I've been getting acquainted with one of the fuse boxes under my hood to get up to speed with the relays found there. I'm walking through the diagram and the table of relays seems to match up very consistently with blank entries (
-) in the table to empty relay slots in the fuse box.
However one relay labeled
FMI2 BIFUEL LPG VALVE has a entry in the relay table but no relay in the fuse box. I'll research more about my car but I'm curious as a general question if there is such a thing as optional relays or for that matter optional circuits in a vehicle?
I guess that might be so with this bi-fuel vehicle thing this relay refers to, I'm only running Gas so it's good I don't need that circuit to be active.
A follow up question would be what's the conventions for these fuse box diagrams, an empty entry in the table would suggest I don't have the circuitry or hardware at all for the devices those portions of the fuse box are capable and intended to support. Perhaps some upgrade hardware passed up at the time of original owner vehicle purchase. Maybe the fuse boxes are used to support multiple vehicles?