[shuotong]

So I did the rear fog light mod yesterday and replaced my old button with the euro rear fog light button, but the assembly is still the old one since mine is a 11.
My button is not illuminated though, and I'm pretty sure the LEDs are on the circuit board, is there a coding to do to make it lights up?
Haven't found anything useful yet as I'm one of the few people who just replaced the button instead of modding it or replace the entire assembly.
If anyone replace the entire assembly please let me know if your button is illuminated.

[6ixSpd]

No such coding there, it should light up on its own. I'd check the LED. It's likely damaged.

[NightStalker]

wait i don't think mine ever lit up either. it did function though

[6ixSpd]

Mine lights up, but I have the full euro switch assembly not just the labelled button on a stock US housing. That is likely why there is no backlighting. The stock US board may not have the LED on there.

[shuotong]

Originally Posted by Red Car

wait i don't think mine ever lit up either. it did function though

Yeah, it is functional, just not lights up.

[shuotong]

I upgraded my interior trim to walnut and have a change to take the switch out again. Nothing damaged, there's simply no LED for the rear fog light button on the circuit board, pretty sure BMW removed this (for North America model) to avoid leaking any light.
On the picture, bottom left side is the rear fog light, you can see there's nothing on it.
I hope this can help someone who'd like to do the same thing, the button is relatively cheap if you source them in EU and China (which is the same spec as EU), just be aware the LED won't illuminate.

[UncleShrek]

Good to know.
So Euro switch is the only way.