Webasto on Thesis JTD

[Isola]

Hello,

The Nordic winter has come and I'm still searching a viable way to pre-heat the car. Does anyone know any technical details on the supplementary heater offered as an option for diesel-powered Theses?

I've understood that the heater is a Webasto Thermo Top C. These can be bought for a more or less reasonable price, but do I need a Thesis-specific control unit for that? Or does a generic Thermo Top C plug in directly to the cabling that should already exist in my car? Probably I need an Examiner to enable the heater menus in Connect (they are there, but greyed out). That's not a problem, but the problem is the controller module with Lancia order code 60677558. Is this a generic controller that comes with an aftermarket Webasto heater, or do I have to find one with Lancia-specific firmware somewhere?

[vlad47]

After connecting everything this grey option in connect will become usable without any examiner. I'm just not sure if you need to pair it, because some control unit cause EOL error after removing or adding to the car. Webasto comunicates via CANbus so you need a specific webasto. If I'm right there's one fiat edition and it should be working. I'm thinking of going to webasto dealer and ask him to reconfigure it for fiat.

[Isola]

Thanks, Vlad. You seem to know a lot about these cars.

I've browsed through the workshop manuals of Thesis and Webasto, and I guess it goes like this:
The heater unit is a plain Webasto Thermo Top C, but with a Fiat/Lancia specific firmware. I assume this because the connectors looks like they are the same on both ends, but 2 out of the 6 pins of the large connector are described to have different functionality. In Thesis, the heater does not connect directly to the CAN bus, but it communicates with the climate control ECU via three discrete signals. There are two mode selection signals to the heater controller and one status signal to the climate control ECU.

Basically I could pretty easily fool the A/C controller to think the Webasto is there by feeding an appropriate signal to the status pin and see if anything happens. I don't really need the timer as I prefer the remote control, but I absolutely must be able to turn on the cabin heater with the engine off. That's why the A/C controller must be made to know there's an auxiliary heater installed. The big question is whether the status signal from the heater is enough to wake it up. Maybe I just have to test that, but I have a feeling that the result of this experiment is negative.

I could ask a Webasto dealer anyway - in fact I already asked for a quotation a couple of weeks ago but haven't yet got any answer. I bet that's a bad sign.

[vlad47]

Sry for such a late reply but I'm not used to be going on this english part of the forum. Well you are right, that's why I'm waiting and discovering everything about webasto in thesis because I really need it to communicate with the car as I can use the cabin heating function because thesis is closing all outlets when ignition is off (I don't need the timer too). The cables to the webasto were added when needed so if we don' have webasto we don't have them. New cables for webasto can be bought directly in any fiat dealer and cost about less than 50€ so I would buy them. Then I'm thinking of buying some thermo top C and ask webasto dealer to flash it for me to the Fiat version. I'm waiting for my friend who has a webasto in his thesis, he will make pictures for me of how it's originally mounted, connected etc.