Webasto AT 2000 - Temperature Sensor? How Does It Work (as In Setup With Controller Etc)

[oldiebut goodie]

Did you have it hooked up to diagnostics to see if the temperature reading had altered in the ecu?
Who are "they"? No Webasto agent/installer has raised this here so it appears that it is Russian market heaters that are affected only which begs the question, are they bona fide Webasto heaters? I would like to see the parameters of your heater to compare it with those of my genuine Russian market STC. It strikes me as odd that this has only been reported by people from the US of A who have purchased them from Russia.
I would change the dataset in the ecu to that from a pukka ecu to see if that will solve the error. Of course I cannot do it until I come across one of those odd heaters - as I said earlier my Russian market one is absolutely normal in software and wiring, I was expecting to get one that was as described earlier without full functions.
I suppose that it just boils down to buying one on the cheap and then discovering that it doesn't function correctly - as in most things " you get what you pay for".

 

[ddn]

No, I did not, but I waited a while for the fan speed to come down and there was no change.

I don't know who "they" is. Don't take it personally. Maybe these are total knockoff heaters, I don't know. If the worst thing is that I can not use an external temp sensor, that will have been worth the discount anyway.

 

[whhite whhale]

Hello, been searching for an answer to wiring up the external thermostat in this thread, and others, plus the electrical diagrams from the service manual. I appreciate all the knowledge found here thus far. But what my eyes see on my heater does not line up with the electrical diagram, or other people's written experience. Where are the #8 & #9 pins in the photo below?

Heater Model: AirTop 2000ST Diesel w/ Rheostat. Had it for 11yrs and no issues!
Trying to install the remote thermastat, Webasto part #9005004C.27319.

Image below of what I see. If you see where to attach the wire connectors, please let me know, and thanks very much!



(Bonus question on high elevation setting: Do you know/see which wire/pin I touch to negative bat. terminal for reprograming high elevation setting? That mystery has haunted me for 11yrs. now.)

Thanks very much!

 

[oldiebut goodie]

For a start that is a 2000 D or S not a ST! Therefore no pins 8 & 9 - totally different heater. You are looking at the wrong wiring diagram most probably if you don't know which heater you have. The model details are on the white sticker on the side of the heater. 2000 manual attached. The S is very much the same.

That part number is for a remote temperature sensor not a thermostat ( Modern heaters do not use a thermostat). The remote temperature sensor plugs in where the 10K ohm thermistor is plugged in at present - bottom right plug. See manual part 9.1.1. ( At least you have the correct part for that heater )
As to high elevation use you have been searching for something that does not exist, the 2000 D and S do not have the grounding wire so you can not use that method as on the ST and STC models. ( Only the STC models can have an actual high altitude switch fitted).

The only way that you can adjust your model's CO2 level for higher elevation is to turn the the trimmer pot anticlockwise to have the heater run leaner that way, if you haven't got a CO2 meter to check the exhaust gases it will be hit or miss as to what setting you have achieved. I would only turn it 5 to 10 minutes angle at the most. The trimmer is the small blue device at the bottom left. For reference, at sea level CO2 should be between 9.5% and 12% for a diesel and 9.5% and 10.5% for a petrol heater.

A high altitude STC model is only rated for use up to 1500m ( just under 5000ft). An Evo 40 or 55 can be used up to 2200m ( just over 7000ft). The older models do not have a rated elevation as there isn't a simple user or factory addition that enables the tweaking of the CO2/fuel ratio.

If you only visit the higher elevations rather than live there it is ok to run on the standard setting for a while, just not continuously for days on end otherwise you can have premature coking problems.

 

[whhite whhale]

Thanks so much! Very helpful, and appreciative.

 

[bas1lbrush]

10KΩ NTC

Is that an alternative way of making a cabin Temp Sensor? If so what would be a good resistor for a 15 Deg C - 20 Deg C cabin temp?

 

[oldiebut goodie]

The sensor is just a 10KΩ NTC thermistor. You cannot pick and choose a single resistor for a set temperature.

 

[bas1lbrush]

The sensor is just a 10KΩ NTC thermistor. You cannot pick and choose a single resistor for a set temperature.

Ok, so all we need to do is to replace the original thermistor with a 10KΩ NTC thermistor (with extension wiring) and that would imitate a Webasto Temp Sensor?

 

[oldiebut goodie]

Yes.
Of course you have not stated what heater you are playing with so it is just a general response.

 

[bas1lbrush]

Yes.
Of course you have not stated what heater you are playing with so it is just a general response.

Webasto Air Top 2000 STC European

 

[oldiebut goodie]

You will not have an original thermistor to replace on a STC - the original on a STC is a chip on the ecu circuit board. You replace the 620Ω terminating resistor that is across pins 8 and 9 in the loom with the new thermistor.

 

[bas1lbrush]

You will not have an original thermistor to replace on a STC - the original on a STC is a chip on the ecu circuit board. You replace the 620Ω terminating resistor that is across pins 8 and 9 in the loom with the new thermistor.

In other words remove the terminating resistor from the Blue/Black wire and add in the 10K NTC Thermistor with extension?

 

[oldiebut goodie]

The colour of the wires to the terminating resistor can vary - sometimes there is a yellow wire. Just cut whatever colour wires have been used and remove the resistor.

 

[bas1lbrush]

The colour of the wires to the terminating resistor can vary - sometimes there is a yellow wire. Just cut whatever colour wires have been used and remove the resistor.

Ok, many thanks for your help. You're a whiz and greatly appreciate it.

 

[bas1lbrush]

The colour of the wires to the terminating resistor can vary - sometimes there is a yellow wire. Just cut whatever colour wires have been used and remove the resistor.

BTW what does the Error Code "F15" mean when in Ventilation mode? Webasto Air Top 2000 STC.

 

[gogoyogo]

Hi all. Can someone please tell me where is terminal 8 and 9? I know they're on the plug that goes into the ecu.
Thanks

 

[oldiebut goodie]

Which heater do you have?

 

[gogoyogo]

Hi and thank you for your reply,
I have 2000 stc which I have purchased from Russia, the harness I bought from UK to connect the multi controller which I also believe I bought from UK and also to connect the rotary dial that came with the unit at the same time, so now I have the two controllers connected and I can control the unit from both controls and also made fresh air and recycle air connected to the air inlet that's why I need to attach the external temperature sensor so I control the temperature inside the RV while using the fresh air, I think I have located pin 8 and pin 9 but I will just wait until you reply so I confirm that I have located them correctly.
Thank you very much for your help.

 

[oldiebut goodie]

You could have answered your own question - the numbers are on the plug! Left to right: 1 & 2 large power, 3 -7 front row, 8 - 12 second row, 13 - 18 third row. I can't see what colours you have for 8 & 9.

BUT...... as you have purchased a cheap Russian market heater you may well have a problem connecting an external sensor to the heater as people in the USA have purchased heaters from Russia and that function is not present in the ecu, it may well be the same on yours.

See this thread: Webasto AT 2000 - Temperature Sensor? How Does It Work (as In Setup With Controller Etc)

 

[gogoyogo]

You could have answered your own question - the numbers are on the plug! Left to right: 1 & 2 large power, 3 -7 front row, 8 - 12 second row, 13 - 18 third row. I can't see what colours you have for 8 & 9.

BUT...... as you have purchased a cheap Russian market heater you may well have a problem connecting an external sensor to the heater as people in the USA have purchased heaters from Russia and that function is not present in the ecu, it may well be the same on yours.

See this thread: Webasto AT 2000 - Temperature Sensor? How Does It Work (as In Setup With Controller Etc)

View attachment 210760

Hello, I have connected the sensor to terminal 8 and 9, the colour of the wires are black with blue stripe, I have run the heater, set it to 25c but it keeps running even I put the sensor Infront of the outlet, now it says on the heater made in Germany ( in Russian ) even though I bought it from Russia,
Any thoughts and advice will be muchly appreciated.
Thanks.