My R55 has ther typical issue where the left reverse light does not illiuminate and was wondering if there is a setting in Bimmercode or ISTA+ that I can toggle to activate the left reverse light short of running a wire over from the right reverse tailight wiring?

 

There is no left reverse light in
man R55. That light is a rear
fog light (when optioned).
It’s not codable as a reverse light.

 

I bought new union jack taillights and the reverse wire is present but not energized so I assume it is able to be coded to direct current to that wire when in reverse.

 

Those tail lights require a jumper between the lights to make the reverse on both sides. No way around that.

 

A couple of ways you can get 2 reverse lights.
Order the UK left side tail light which has the reverse light on the left instead of the right, then jumper it across https://www.northamericanmotoring.co...se-lights.html
Buy aftermarket tail lights which include a jumper and have reverse on both sides: https://www.northamericanmotoring.co...ml#post4674305

What's your goal? Needing more light when reversing or just wanting symmetry? My rear windows are pretty dark, so even with a bright LED bulb I needed more light. You can also add additional reverse lights. I have one of these sitting on my workbench to go on eventually. It will bolt to the bottom of my license plate mount and tuck in under my bike rack.