CAN adapter for Webasto auxiliary heater | Posts 16+

Hello everyone,

I'm studying to become a technician in automation and mechatronics. We are currently using the PIC 18F4580 microcontroller in school, and I want to test it first to see if what we're planning is even possible. However, I've been searching for several days now for the W-bus protocol from Webasto. Does anyone have it and can send it to me? Also, how is the W-bus actually structured? I've seen that it's a single-wire bus. Is it a LIN bus? And what data does the Thermo Top require, and what data does it provide back? I've already contacted Webasto but haven't received a response yet. Can you help me? Also, I was thinking about this: In my case, I have an auxiliary heater from a T5 that I want to use for testing. Of course, it doesn't have the water pump, and I would like to control it directly via a relay connected to the microcontroller as soon as the request comes from the CAN bus. This way, I can avoid all the complicated modifications of turning an auxiliary heater into a stand-alone heater using wiring harnesses or something like that. What do you think? ihr?

Best regards,

Jürgen.

Hello Jürgen,

wenn du ein paar Beiträge weiter oben geschaut hättest, dann hättest du den Link in meinem Beitrag gefunden.
DiThe kids have revealed the protocol of the W-Bus: <!-- m --><a class='postlink' href='http://libwbus.sourceforge.net/'>http://libwbus.sourceforge.net/</a><!-- m -->
As you correctly wrote, the W-Bus is a single-wire bus.
More precisely, it's a K-Line bus.

Best regards,
Maxx.The boys have revealed the protocol of the W-Bus: }}}}}Best regards,

Hello Maxx,

'Thank you. I apparently completely overlooked that in my haste. I thought it couldn't be possible that I wouldn't find anything here.'

Best regards,

Jürgen.

@Maxx

What vehicle does the CAN command set I found in the other thread, which is used to control the heating system, originate from? Is it the same across all vehicles within the Volkswagen Group?

Best regards,

Jürgen.

Der müsste bei der PQ35 und PQ46 Platform passen.
Best regards,
Maxx.Best regards,

hello everyone,

habe ein ähnliches Problem wie ihr, nur andersrum...
I want to install a CAN-bus auxiliary heater in a car that doesn't have a CAN-bus, and I am also interested in a suitable converter. However, this converter should not convert from W-bus to CAN-bus, but instead send the start command via CAN-bus based on an analog switching signal.

Background: I bought a Webasto Air Top 2000 ST from a Mercedes Actros. I want to install it in a MAN L2000 (which apparently doesn't have a CAN-bus). Unfortunately, the 2000 ST only has 8 wires connected, and none of them seem suitable for switching, probably not even W-bus, but it does have a CAN-bus. If my online research is correct, the Air Top always runs at maximum power after being switched on in the Actros, and the air conditioning system only adjusts the temperature by controlling the fresh air intake. This means that the climate control unit and auxiliary heater are constantly communicating via CAN, and this CAN bus is likely specific to Mercedes.

Unfortunately, I don't know if the CAN commands are identical to those of your ThermoTop, but I doubt it. Also, my CAN-bus will probably be running at 24 volts, which makes things more complicated. If you have made progress with your problem, it would be great if someone could contact me. If anyone else has data that could help me (e.g., the communication protocol of the auxiliary heater in the Mercedes Actros), I would appreciate it.

I was thinking about a solution using an AVR and a 24V CAN-bus chip, but for now, I would also be happy with a USB version. Does anyone know if there are any USB adapters for the CAN-bus in trucks?

Thank you in advance.

Best regards,
propofolI want to install a CAN-bus auxiliary heater in a car that doesn't have a CAN-bus system, and I am also interested in a suitable converter. However, the converter should not convert from W-bus to CAN-bus, but rather send the start command via CAN-bus based on an analog control signal.Background: I purchased a Webasto Air Top 2000 ST from a Mercedes Actros and want to install it in a MAN L2000 (which apparently doesn't have a CAN bus). Unfortunately, the 2000 ST only has 8 wires connected, and none of them seem suitable for switching. It likely doesn't use a W-bus, but does use a CAN bus. If my online research is correct, the Air Top always heats to maximum after being switched on in the Actros, and the air conditioning system only adjusts the temperature by controlling the amount of fresh air intake. This suggests that the climate control unit and the auxiliary heater are constantly communicating via CAN, and this CAN bus is likely specific to Mercedes.Unfortunately, I don't know if the CAN commands are identical to those of your ThermoTop; I doubt it. Also, my CAN bus is likely running at 24 volts, which makes things more complicated. However, if you have made progress with your issue, it would be great if someone could contact me. If anyone else has data that might help me, please let me know.I was thinking about a solution using an AVR microcontroller and a 24V CAN chip, but for now, I would be just as happy with a USB version. Does anyone know if there are any USB adapters available for the CAN bus in trucks?

Thank you in advance.

Best regards,
propofIs there anyone who knows if there are any USB adapters available for the CAN bus in trucks?

Thank you in advance.

Best regards,
prThank you in advance.

Best regards,
propofThank you in advance. Greetings.

Hi!

Gibt es für die Webasto Air Top 2000 ST auch eine Funkfernbedienung?
If so, then your heating system also has a W-BUS.
You should research this first.
The CAN telegrams between VW and Mercedes are definitely different.

Best regards,
Maxx.Best regards,

Hi,

Typically, Webasto Thermo Top V auxiliary heaters, which are only auxiliary heaters, do not function with the 1533 timer via the W-bus. This has nothing to do with 'only CAN-bus.' Every Thermo Top V auxiliary heater, parking heater, etc., supports the W-bus at least for diagnostics. The rumor about 'CAN bus only' originated on langzeittest.de and is a pure invention without any factual basis (sometimes, things are quickly presented as amazing and self-evident facts based purely on imagination ). The problem is simply that the heating command sent by the 1533 timer is ignored because it is not implemented in the heater itself. The 1533 timer does nothing else.

Using the Data Top diagnostic software from Webasto, you can read out the so-called 'W-Bus Code.' Each bit represents an applied feature; don't ask me which bit corresponds to 'standby heater command support' – you can find that information yourself in the libwbus source code.

You can still use the 'preheating' command (0x23 instead of 0x21). The disadvantage is that the fuel preheating function and the passenger compartment blower output will not be activated. Personally, I think it's more sensible to sell such a device on **** and get one from a Golf V (they are usually equipped with auxiliary heaters that support the 0x21 command). If you connect a diagnostic tool like Data Top, you can quickly see what's going on (the heater button will be grayed out and there will be a corresponding code in the W-bus).

Bezüglich CAN Datagramme, wäre schön wenn diese mal jemand veröffentlichen könnte.

GrüDear [Name],

Best regards,
Manuel.

P.S.: Never use tinned wire strands; use ferrule sleeves! Tinned wire strands will definitely come loose in the winter due to ice and snow.mmen.Greetings,PS: Never use tinned wire strands; use solid core wires! Tinned wire strands will definitely come loose from the connectors in winter due to ice and snow.