jseklund

Ummmm.....I am unaware of a yellow COOLANT light.

Is it a yellow light that is animated and has "fluid" shooting out the top of a can? If so, your windshield washer fluid is low, not your coolant.

jseklund

https://www.audiworld.com/tech/elec57.shtml

Second image from the left....is the yellow part of that image what you are seeing?

Osmosis

After further dianosis, I figured out that I'm a ReTard.

Windshild washer fluid low

My First Audi.... I looked in the owners manual and low and behold...the answer

jseklund

lol, yup....hey, I've owned audis for a long time and it took me a day to figure it out

SloopJohnB@mac.com

Yes..when all else fails read the owner's manual.
Been there, done that.

CRuby

So did filling up W/W reservoir fix the problem or not? I hope so, for you.
I have same 'low w/w fluid level" warning light, even with full tank & new sensor. I've discovered this part & others share a ground wiring (ground 269) that is not grounded. Does your light dimmer switch work? This is another component that shares ground 269.