While cleaning my engine bay I noticed this harness by itself not connected and part of the clip broken. Does anyone know what this is or does?
It's by the brake master cylinder (driver side). My car is an '00 AP1, I have no Check Engine lights or throwing any codes at all. Car and all lights/electronics operate normally. I do however have an aftermarket alarm.

 

That is a comm link connector that a mouse chewed pieces off of, revealing an open plug. It is not supposed to be connected to anything. So its normal. Just tape it up and you are good to go.

 

Thanks Billman! I couldn't find it in my service manual, figured i ask here

 

You can see the teeth makes from the mouse on there. It has a softer rubber that mice like to use for nesting.

There is very likely a small nest starting in your car

 

not to mention the mouse poop that is below that harness

 

Sometimes my S stays parked for 3 weeks or more before I drive it. I keep a mouse trap under the hood on the front cross beam. I have killed 5 mice in the last 2 years

 

quite a lot of mouse droppings down there wow! i better give the S a regular driving.