My 2006 B7 A4 2.0 T FSI has been having intermittent issues on my HUD with regard to coolant level. There are certain times when I start the car that it will perform the check and come back with no issues, just the normal "ok" and other times the coolant level indicator stays lit up and will not go away. Obviously, I've checked the coolant level, and while it wasn't really low, I filled it up to just below the max line. However, the issue is still present.
Today, I took apart the ECU module cover and checked the wiring harness for any shorts in the connection to the reservoir as well as the sensor itself, there appear to be no issues with either. Has anyone else run into this issue and what had to happen for it to correct itself?
Can the sensor be replaced itself, or is it part of the reservoir? What about the connector (2 prong connector that plugs into the sensor wired into the electrical system of the vehicle)?
Thanks for any help offered, I greatly appreciate this site and will return the favor on other issues I've encountered and fixed myself.

Ian

 

It's in the bottom of the coolant bottle, part of the bottle...if your coolant is full, the sensor is either faulty, requiring reservoir replacement, or the coolant was low, tripping the switch, and now it's stuck...in that case, you can try tapping on the bottom of the bottle without breaking it...it can be tricky, but should come loose as long as there's coolant in it.
good luck..

 

I tried a few various things such as cleaning the sensor, taking some of the reservoir fluid out and putting in fresh coolant, with no luck. Does anyone know of where to get the replacement reservoir can't seem to find it on ECS tuning. Is there anything else I can check before replacing the reservoir? Fuse? Wiring harness?