Webasto multicontrol not working

[c_paul]

I have a Webasto thermo top evo in my 2016 t6 with climatronic.

I am converting it to a parking heater and have flashed the firmware to …272B

I don’t have a telestart module (yet?) but do have a Multicontrol.

If I set the aux heater’s coding to 5101 (remote control with no screen) then if I try to start with the Multicontrol it fails with a T12 error. A comms error between the multicontrol and the heater.

If I set the coding to 4101 it doesn’t error. The pumps start up but the heater immediately shuts off with a system malfunction. It is as if it is not getting acknowledgement that the pumps have started.

If I change the coding so the pumps / fans are direct rather than can bus, I get relevant errors on the Multicontrol which implies there is 2-way comms between the multicontrol and the heater.

All I can see (logging through vcds) is the operating mode is set to start via bus controller, then shut down due to malfunction then lockout / burn-out / cooldown about 0.2s later.

Any ideas?

I can’t get any sensible diagnostics from vcds. The message happens too quickly. I am thinking my next step will have to be make a patch cable to try and run wtt software talking directly to the heater.

But I am hoping someone else has had this / has some ideas.

Help!??!

 

[oldiebut goodie]

You haven't got the black wire connected to the Multicontrol have you? If I remember correctly this can cause such problems.

 

[c_paul]

Nice thought but nope - definitely the yellow w-bus wire from the control panel. The fact that the control panel behaves differently if I change the heater coding from 4101 to 5101 suggests to me that it is not a wiring issue.

 

[oldiebut goodie]

You may well have the yellow connected but is the black connected also? If the black is connected at all to the Multicontrol you will have problems as you will have two conflicting signals.

 

[c_paul]

Black is definitely not connected to anything.

 

[rippelep]

Just a question, if you flashed …272b, if it is the oem software, are you shure it should work with multicontrol? From my knowledge it just works with webasto software (w-bus)

 

[c_paul]

Just a question, if you flashed …272b, if it is the oem software, are you shure it should work with multicontrol? From my knowledge it just works with webasto software (w-bus)

I have HW 7E0963273A and flashed it to SW 7E0963272B from a download in the forum. The controller I have is a Webasto 9030911D that, from my understanding, will only talk to the heater using w-bus (pin 1 on the red connecter).

My understanding is that the FL_7E0963272B__0009 firmware is the Webasto firmware not the VW OEM firmware which would mean the controls now all need to be Webasto w-bus and not VW OEM Lin-bus.

The fact that the heater is momentarily reporting a status of 'Parking heating via external data bus' suggests that the w-bus bit is working but because there is no telestart installed (and coding is 4xxx instead of 5xxx, the message from the Webasto to the VW can bus is being rejected. If I change the coding to 5xxx then I get totally different errors because it can't talk to the telestart.

But I must admit, it is rather confusing. Trying to work out which versions of which would work with what. And none of it is supported / documented. Eventually I will get a T91 but this wont arrive soon - and I am not sure if I need the Lin version or the version without. ???