LC200 MY16+ - TOW BK/UP Fuse - what does it do?

[martinpescatore]

Hi all,

I'm trying to understand what the fuse TOW BK/UP does. It is located in the passenger side (if you are USA) or driver side (AU) fuse box.
Searching online I can find it's related to Towing which is weird... I have a 7 Pin Flat towing plug installed by Toyota and all the PINs on the plug work with or without this fuse.
Unfortunately I don't have access to any service manual to find out more and I was wondering if anyone knows?

thanks in advance, Lorenzo

 

[CharlieS]

On my US model, this sends power to the center pin of the 7 pin round RV plug. This drives reverse lights.

 

[martinpescatore]

Thanks Charlie,

this is even more odd then as I believe this fuse has constant power and I wouldn't think reverse lights would need it

 

[CharlieS]

On my vehicle, there is also a relay behind the glove box that enables power to that wire on the tow plug when the vehicle is shifted into reverse. I tapped this circuit for auxiliary reverse lights through my Switch-Pros.