Problems with the comfort control unit

Hello everyone!
I'm having a strange problem with a Passat 3BG Variant.
"Due to improper installation of an alarm system, the comfort control unit was damaged, which I have already replaced (ordered from VW using the vehicle identification number). After installing the new unit and pairing the remote keys, everything seems to work fine except for the tailgate unlocking function via the remote control and the unlock button in the driver's door. The position of the tailgate lock is correct. In the diagnostic data block, these functions are also displayed as being okay, but they don't actually work. Also, no error codes are stored in the fault memory. What could be the cause?"

Which control unit (part number with index) is installed, and what is the current coding?

I'm just having a moment of brain fog... it must be due to incorrect coding.

I spoke to the customer service representative again earlier, and he told me that the unlocking button on the Variant is completely non-functional to prevent cargo from being lost during driving. Strangely enough, this isn't mentioned in the vehicle's manual. Instead, it describes using the button to open the trunk. Also, the button on the remote control is only intended to unlock the tailgate if the doors are locked, which can then be opened manually using the button on the tailgate itself. To me, it all seems illogical because the signals are connected to the central control unit and are also displayed in the diagnostic data block. And then there's the fact that VW installs a button in a vehicle from the factory that is then non-functional. I've tried all the coding options, even the ones that seem completely illogical (which isn't usually my approach), but I always ended up with the same result. I also couldn't find any further information in the repair manual (Elsawin); it just lists the same coding options as Dieselmechanic.

If you provide specific part numbers, including the suffix and index, we might be able to help you. It's not uncommon for the wrong part to be delivered when ordering based on the vehicle identification number (VIN). The coding itself isn't usually the issue; rather, it's often a parameterization problem. Therefore, it's important to know the complete part numbers of both the old and new parts...

In our company's Passat, manufactured in April 2004, the button for unlocking the trunk and also the button on the remote control are both completely non-functional. This has been the case since the beginning (although no one has really bothered with it so far). I will mention it during the next inspection.
"On our Ford Focus (manufactured in 2003), there is also a button that works perfectly. As soon as the car is moving, this button is deactivated to prevent accidentally opening the trunk while driving."

The function of the third button on the key fob for the tailgate has changed.
If you press the button once while the car is locked, then...
The tailgate unlocks and can be opened without unlocking the entire vehicle.
unlock. But most people don't understand that.
Previously, pressing and holding the button would actually unlock the tailgate.

Regarding the problem mentioned above, I also think it might be related to encoding issues.
I would go to the friendliest ones and politely ask.
Or you can come visit me as a friend.


Hi Mattes,

It's not a coding issue; it simply can't be, if you look at the coding options available for comfort control units of generations II and III.