Webasto Sim Card Issue

Ian28

Senior Member
T6 Guru
My Webasto diesel heater has a SIM which allows me to start/stop it via text. It’s stopped working - presumably because I never topped it up and 6 months expired. I’ve topped it up online (Tesco mobile) but it still won’t respond to texts. I contacted Tesco mobile & they say the SIM is showing as active and I should try taking the card out & putting in a phone to see if it is functional.

Makes sense to me but where do I find the SIM card? I think it uses the ThermoCall 4 technology so I’m assuming there’s a unit somewhere.

Anyone had a similar issue?
 
Hi @Ian28, you should have an antenna stuck to a window somewhere (a black, flat, rectangular lozenge maybe 10x2cm), the unit will be on the end of that - not sure how long the cable is but my antenna is stuck to a rear window and unit is directly below it, inside a cupboard...

When working if you call it directly you should get one ring before hang up, at least I do :thumbsup:
 
Thanks @Hah! - found the lozenge on my windscreen behind the mirror. The cable runs into the compartment above the ceiling so not easily accessible. When I call the number it goes to the Tesco mobile messaging service which suggests to me the card works and is receiving my call. Might pop in to Tesco tomorrow to see if they can help.
 
I don't think the antenna cable is so long it would run down an A pillar to somewhere under the dash, bet the unit is in or near the overhead cubby/light pod somewhere, like maybe under the blank here:

AC07190A-756F-4C50-BFF9-D49C2CDB772C

It does sound like a SIM issue to me. If you are being passed straight to messaging before ring would it not indicate number is not connecting rather than not being answered?
 
Yes sorry that’s the bit I meant when I said ceiling! Does that plastic blank cover pop out easily to access the space? Think I’m just going to get another SIM installed and get the new number put into the Webasto App on my phone then hopefully all will work. I suspect you’re right about the message too - I’m not great with technology. The flashing code on the dashboard light (2 flashes per second) is indicating a SIM/network issue according to the ThermoCall PDF.
Appreciate your assistance here, cheers, Ian.
 
I was recommended to use an Asda mobile sim by the Webasto Rep. 50p from Asda with 10 mins & 10 texts included. It’s worked flawlessly at home & abroad. The only thing I get is an occasional reply text saying that the command is old & cannot be carried out, this happens when I tell it to switch on. This is due to crossing time zones when travelling abroad. There is a text command to send to the unit to reset it.
 
Pops out fairly easily with a trim tool, light unit is a bit more complicated though as you have to remove lens, bulb and undo a screw before removing. If you do a bit of searching on here there are pics and instructions to remove somewhere about - the above link was in my private stash and there is more pictures in the series linked to :). Not sure I've been too much help but every little helps, good luck :thumbsup:

(+1 for ASDA too...)
 
Last edited:
I'm about to bin my Tesco sim and replace it with an O2 sim, on their Classic tariff. 2p a text, so cheap if you use the request 'status' function.
 
I went with Giff Gaff on mine, I don't think the credit ever expires, so £10 of texts should last for quite some time.

Edit - do you have an led that flashes to show you have service?
 
Yep, there’s a flashing light on the dashboard indicating that there’s a network/SIM fault although Tesco mobile say it should be active. I’m just going to put a new SIM in and be done with it. Just need to get to the SIM now...
 
362C3209-CDC0-449B-8841-613790338467.jpeg 4492F060-1042-405D-AAB4-2BE47688CED1.jpeg 6D630D02-7100-4015-A7CE-5F9549129C5C.jpeg Update - still can’t find the ThermoCall unit that will have the SIM card in it! I removed the interior light cover & unscrewed the lights to give access and found a wee black box with VW details on it - looks like something electrical but not the ThermoCall. The cable from the ‘lozenge’ heads into this area but the cable from the Webasto control (red mark on photo) heads off towards the sun visor area under the headlining. Could the ThermoCall be behind this & if so how do I get at it to change the SIM? Have also emailed the converter but would nice to resolve it myself. Thanks everyone for all the help.
 
Update - took all the trim off around my heating controls/radio as well as around the steering wheel, also removed my lower glovebox completely. Still so sign of my TC4... It’s a comfort dash & the only bits I couldn’t remove were the top tray which appears to be moulded in and the upper glove box which felt like it was going to snap. I also didn’t take the radio out completely but maybe I should have?
I’ve asked my converter but anyone else got one and of so, where is it?
 
Telestarts' receivers are often sited under the passenger seat - might be worth looking there rather than pulling everything apart.
I will look around for instructions on re-pairing with the receiver, that may be all that is needed.

Beaten to it!
 
Will look there tomorrow in the light - my lithium leisure battery is there but I guess the TC4 could be too. I didn’t know the unit could be repaired with the SIM - I’ll Google that too since the SIM is apparently still active. Need to find the bugger first though...
 
Back
Top