Coolant temperature sensor 2 location

[Andy Johnstone]

Evening all,
I seem to be chasing a bit of an issue on my van. Last week I had exhaust gas temperature sensor Bank 1, Sensor 2 showing a fault. I have replaced this sensor now and the fault has cleared, but as soon as I replaced it, I am now getting the red coolant warning and 3 beeps on start up and the coolant temperature dial isn’t giving any reading. I’ve scanned again and I’m getting coolant sensor 1 showing a reading and coolant sensor 2 showing -40deg. Is it a coincidence that this has failed right after changing the EGT sensor?
I know there’s one coolant sensor at the bottom of the radiator behind the bumper, is this the sensor I should be looking at?
Appreciate any help!

 

[mmi]

coolant sensor 2 showing -40deg.

Hmmm... on the second line

thus the reading shows -40 ℃ = open circuit. Which is correct for T6 engines.

 

[Andy Johnstone]

Hmmm... on the second line
View attachment 236918
thus the reading shows -40 ℃ = open circuit. Which is correct for T6 engines.

Didn’t even see that! ‍ thank you!

If I’m showing a reading on the temperature sensor from the live data on the scan, but not in the vehicle, do you have any idea what that could be then?

 

[catfood12]

It could be the old G83 sensor problem;

EML/CEL and radiator fans running constantly

After around 700 miles of mainly motorway driving last week, I got a CEL. Also noticed that the radiator fans were running constantly. That was when I arrived home after a long drive, not stuck in traffic. Same next morning from cold, CEL and fans running constantly. Van still ran well, it did...

www.t6forum.com

 

[mmi]

If I’m showing a reading on the temperature sensor from the live data on the scan, but not in the vehicle, do you have any idea what that could be then?

No fault codes? Would expect have one if the Engine and the Instruments were not communicating.

The engine coolant temperature is available also in controller 17-Instruments though slightly adjusted.
In the thread below both values were plotted just to show VW's smoothing algorithm on dash gauge.

[T6_measured] Winter specialities

Spot the winter specialities:

www.t6forum.com

The 17-Instruments has a couple of diagnostic tests - one of them is temperature gauge sweep - to verify the actual dial operation. Perhaps your tool can run those.

In VCDS

 

[Andy Johnstone]

It could be the old G83 sensor problem;

EML/CEL and radiator fans running constantly

After around 700 miles of mainly motorway driving last week, I got a CEL. Also noticed that the radiator fans were running constantly. That was when I arrived home after a long drive, not stuck in traffic. Same next morning from cold, CEL and fans running constantly. Van still ran well, it did...

www.t6forum.com

I was reading your thread on this yesterday with a lot of interest actually! Now I’ve lived with it for another day or so, I’m leaning towards a sensor issue. If I drive for a bit and get the engine up to temperature, then restart, it works fine. It’s as if it doesn’t like reading from a cold start.
New sensor will be here today so I can start working my way through that, thank you.
It’s weird that it isn’t throwing and fault codes or CEL.

 

[Kaph]

Did you find the problem?

 

[Oakley1306]

I was reading your thread on this yesterday with a lot of interest actually! Now I’ve lived with it for another day or so, I’m leaning towards a sensor issue. If I drive for a bit and get the engine up to temperature, then restart, it works fine. It’s as if it doesn’t like reading from a cold start.
New sensor will be here today so I can start working my way through that, thank you.
It’s weird that it isn’t throwing and fault codes or CEL.

Hi mate. I have the exact same issue with my t6. Did you find the cure for yours? I’ve changed the sensor in the bottom radiator hose and the sensor in the cylinder head and it still doesn’t work correctly when cold. Any help would be appreciated as I’m pulling my hair out with it now.