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Discussion Starter · #41 ·
How were you able to hook up the VAG COM to the webasto unit? I have the software and I’ve selected the right com port and I have pin 7 to the blue multi control wire pin 16 to red and pin 4 to ground. However, nothing seems to happen when I start diagnosis. No errors either. I have also verified that I have the drivers for the chip. I was wondering if you had issues with connecting the vag com cable to the webasto harness at all. It’s a brand new cable that I bought off Amazon but I’m worried it might be broken or not standard. Thanks!
My knock-off VAG COM OBDII connector works just fine connecting to the unit and I have total control over it. I double checked my pinouts and those are what I am using (see photo). Make sure that you are selecting the correct unit from the left side of the first screen of the Webasto Software (see photo.)? Double check you are tapping into the correct multi control wire? My OBDII connector has a LED light to let you know if it is powered up - maybe check this as well? Double check you are on the right COM port (this was a major headache when I first started using these for my VWs)!

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My knock-off VAG COM OBDII connector works just fine connecting to the unit and I have total control over it. I double checked my pinouts and those are what I am using (see photo). Make sure that you are selecting the correct unit from the left side of the first screen of the Webasto Software (see photo.)? Double check you are tapping into the correct multi control wire? My OBDII connector has a LED light to let you know if it is powered up - maybe check this as well? Double check you are on the right COM port (this was a major headache when I first started using these for my VWs)!

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Thanks for the quick response! I think I have a slightly older version of the software. I selected WBus as it said it supports all newer models. I also tried the "automatic search" mode that cycled through all devices, but none worked. My Webasto is Russian-market variety and bought this august. It is an Air top 2000 stc. I have tried connecting pin 7 (purple wire in your photo) to both the multi controller blue wire, multi controller white wire, and the green wire in the brown-green pigtail near the heater (which I believe is supposed to be the diagnostic wire). The OBDII lights up when I plug it into the USB port on the computer whether or not anything is connected so it is getting power but doesn't say anything about signal. It looks like the pins inside are at least connected, but I don't know enough to know if the OBDII is connected to the pins correctly inside of it. I'm assuming that the OBDII works, but I'm not convinced that it does. I set up the com port correctly in WTT and verified the drivers are right and the com port is consistent to what I'm telling WTT from device manager. I have all of this set up in a windows 10 VM with WTT installed inside of it (I found a copy somewhere online and didn't want to risk putting a virus on my computer). Would you be able to post a picture of how you connect the three wires to your multi control harness? I have found a few instructions online of how to do this and I'm pretty sure I am consistent with all of them. Perhaps my software is invalid... the link that you posted in your original post to the instructions has a broken torrent so I got a different version.
 

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Hi all - I feel pretty comfortable with the high-altitude adjustment procedure, but a follow-up question: Does the adjustment need to be done while at altitude, or can you do the adjustment anytime? Hopefully not a dumb question, but I have not seen that clearly stated anywhere. (I've got a Russian unit so no "official" tech support for me.)
 

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Older thread here, but figured I'd respond with the information I got from Webasto tech directly regarding the altitude adjustment for anyone looking for this solution.

"If you have a rheostat dial to operate the heater this is possible. However, you will need a Co2 meter when making the adjustment. This is a crucial step to understand what you are changing it to. This must also be done at the altitude you are at. Best course of action would be to take it to a Webasto dealer. I will say that 10K ft. is twice the approved operation ceiling for the Air Top 2000STC. This adjustment is not a cure. You may still have issues at start up with use above the 5K ft. ceiling, not covered by any warranty."
 
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