Hi there,

               I drive a 2017  Yeti 2l TDI outdoor. 

At the moment, the coolant temperature warning light  is staying on (yellow) when the engine is running.

The temperature gauge is NOT showing as overheating and the coolant level is okay.

No other obvious signs of the engine running hot.

I want to check the coolant temperature sensor and replace if need be.

 

It appears to be located on the coolant reservoir but I just wanted to make sure that was it or if I need to look elsewhere.

 

Once I've confirmed the location, how do I properly remove  and test it?

 

Hope there's a simple solution.

 

Kind regards and TIA, Malcolm

The CTS is a common failure, but ideally a scan will confirm this before throwing unnecessary parts at the car, its location can be seen in this video, it’s at the rear of the block not in the expansion tank. 
 

https://youtu.be/PlfoTKb2KHA?si=cr_818gxlawYVxEW 

Thanks Gizmo. Not as easy as I thought. I may need to watch it a few times before attempting 😁

 

As a matter of interest, what is the part attached to the side of the reservoir? The one I thought was the sensor.

 

Thanks again.

53 minutes ago, malk24 said:

It appears to be located on the coolant reservoir

 

I would be very surprised if that were the case.

 

Are you sure that the yellow light is not to indicate a low coolant level? The sensor you speak of does exactly that and a build up of schmoo on its exposed contacts can cause it to show a low level when all is well, that said yours may well be low.

20 minutes ago, malk24 said:

Thanks Gizmo. Not as easy as I thought. I may need to watch it a few times before attempting 😁

 

As a matter of interest, what is the part attached to the side of the reservoir? The one I thought was the sensor.

 

Thanks again.

The sensor on the expansion tank is for the coolant level.

Thanks JR and Warrior, I will remove that and give it a clean, see what happens. The coolant is definable not low so maybe the sensor is just clogged up as you said.

Regards, Malcolm 

@malk24 The coolant level sensor is notorious for generating spurious overheating/low level errors on a cold (like left overnight cold) engine. If you can see the sensor prongs in the expansion bottle (not all cars) just run a wide flat screwdriver down both prongs 2 or 3 times and that should clear the issue for a year or 2.

Cheers, I'll try it