Remote Controlled Parking Heater

SnotColour

New Member
Hi there guys!
I've decided to get my recently purchase A2 fully winterized by hacking into the webasto, allowing it to preheat the engine without the need for the main lump to be running and circulating coolant. Plan is to build my own little remote control unit with basic open source wifi / 433mhz hardware.
I have a good electric coolant circulation pump which I will plumb in soon, all I need to know is if it is possible to trigger a (diagnostic?) mode to make the heater start up without some sort of official kit or programming intervention from Audi. Already worked out how to get the interior fan running without the ignition being on, last stumbling block is the webasto...

Anyone seen or heard of this being done before?
Appreciate any tips, it's cold up here in Norway!

Cheers
 

Pinkythelabrat

A2OC Donor
There is a free program from Webasto called Thermotest or similar which allows direct connection to their devices and diagnostic testing including making them run. I’ve never managed to get it to work myself but it is certainly supposed to be possible.

Our heaters predate Wbus and use the CAN system to run the heater. It’s theoretically possible to produce an arduino which mimics Canbus or Wbus so it should be possible.

Other options:

You an buy a device of this nature from eBay which Claims to work in this manner and costs about £50.

https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.co.uk/ulk/itm/162776404068

Alternatively you can buy an aftermarket control board which allows a 12v to pin1 signal to trigger on.

https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.co.uk/ulk/itm/162794116122

All of the necessary start up, run, maintain temperature, shut down etc settings are controlled Within the device itself. You can buy a standalone ThermotopC for about £800 used which is the same heater with a different control board. Audis and most manufacturers) have the heaters deliberately blocked against what you are trying to do to preserve that market. They cost a lot more new.

https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.co.uk/ulk/itm/291162041291

There are plenty of videos and information on using arduino for this but most just seem to either use ThermotopC from Rover75 or Peugeots which are 12v pin1 triggered. One guy did a Jaguar thermotop V very nicely but it uses Wbus.

https://www.experimental-engineering.co.uk/jaguar-s-type-aux-heater-webasto-thermo-top-v-part-1-teardown-cleaning/

Good luck and I look forward to seeing your progress. I have not managed to progress this at all myself. But I’m not very good...




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Pinkythelabrat

A2OC Donor
Oh and you need a USB to serial cable to connect to the Webasto directly. Unless you have a laptop with a COM port - I couldn’t find one of them.

The pins on the Webasto are well described and I believe that there is a built in control for an electric circulation pump - never confirmed because ie never gotten it working (no time).

I’m not going to give you the information I have because mine doesn’t work but one of the pins is a diagnostic info line apparently. The others are power, fuel pump signal, earth.

Good luck.


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Pinkythelabrat

A2OC Donor

Pinkythelabrat

A2OC Donor
If you have the German link that’d be awesome.

As far as I could find that Oval timer/controller wouldn’t work because our generation lacked the WBUS protocol. I’d be super happy to be wrong though.

The Disco3 website guys have a great explanation on their forum for all of this but, like I said, it seemed to use a newer model of Thermotop and I couldn’t replicate it and I wasn’t shelling out £80 to try.

It’s a cheap fun project for me. I’m not chucking money at it.


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SnotColour

New Member
Fantastic replies!
From my basic understanding of German I have surmised that a relay triggering 12v on PIN 1 on the Webasto loom should get the unit up and running. Not quite sure if the inline water pump stays on whilst the engine is running if connected directly to the Webasto, I might have to run it from a separate relay as preferably (in my mind) it should shut off when the engine pump circulates. I'll be using an Esp8266 to control everything at first, upgrade to something longer ranged later. Cheers for the writeup Pinky and bretti! Luckily it seems that analogue converters just aren't necessary, I'll post once there's a further project development...
 

Pinkythelabrat

A2OC Donor
So I was reading the Audi A2 2001> Additional Heater technical manual last night...

and it appears that all of the functionality required for using the Webasto Additional heater in our cars as an Auxilliary or Parking heater is already there within the unit - but turned off in the coding.

A V55 circulation pump would need to be fitted but the electrical connection on the heater is there.

The manual refers repeatedly to ‘not currently active on A2 model’ and describes the needed coding modifications for activating. A 000011 becomes a 000021 for example. This appears to allow for activation of the V55 water pump with all the battery voltage monitoring and thresholds and overheat shut offs etc maintained.

It appears the heater was common to the A6 and A8 units which had Auxilliary Heater as a speccable function.

I’m going to need to have a look on VCDS and see if the software is the v50 or later as described...


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