Mod One Touch Up Down Rear Windows

by: TheAmazingDave


First: This mod is not for the faint of heart. It's not that it's difficult, but it will try one's patience and skill. This is also totally driver personal preference. No one can see this mod, and no one would probably realize WTF you're talking about if you tried to tell them about it. My motivation behind this mod is that when you look at the core of it, it reveals that there is likely an option to have this from the factory (as the provisions for it are already there) and being an OEM Dub whore I must add every option that I feasibly can. And one day if I ever must part with my baby, I get a kick knowing that the next owner will have such a unique Passat and they'll never really realize it.

Next: As I've mentioned several times, I didn't figure this process out on my own. I searched the intranetsweb and found a fellow by the name of "madelgado" who is just as crazy about factory modding as I am. His loose instructions were intimidating enough for me, but I muscled through it and ended up with the correct final product. I am taking his directions and expanding upon them, providing step-by-step detail and pictures where absolutely necessary to make this a much more easily understood modification.

Finally: I am doing this write-up now for two reasons. First and foremost, I am incredibly bored. Next, I purchased a new set of switches and since the bulk of this mod is hardware changes to the switch assembly itself, it was necessary to mod the switch panel again.


1. These instructions are for B5.5 -or- 1C0 CCM cars with CAN-BUS, 1C0 being the first subgroup of the CCM's part number. I do not know if the coding changes, or even if the data bus of B5 or non-1C0 cars, will support this modification.

2. You will need a version of VDS-PRO that can perform serial reads and serial writes to the car's modules. You will need a computer with a built-on serial port. You will need a serial OBD2 diagnostics cable. A serial VAG-COM cable will work, but the VAG-COM software will not help with this mod.

3. You should have some basic modding skills, including familiarity with a soldering iron.

4. If you hose your car or any of your parts attempting this modification, I am not responsible. I am providing this information for you for informational purposes only. If you attempt to follow my guide and you mess up, it is your responsibility. I won't be sending out any new window switches if you "let the smoke out" of yours.

* T-6 Torx Driver
* Xacto Hobby Knife w/ Fresh Blade
* Super Glue
* Small Standard/Flat blade Screwdriver (not pictured)
* Donor Master Window Switch Assembly

Modifying Switch Rockers for Multiple Positions

The multiple positions on the front switches are created by small plastic plungers. When these are not present, the rocker is free to cover its entire range of motion without resistance. When the plungers are installed, the tip of the plunger catches a detent in the rocker, causing it to stop halfway through its range in each direction. Here is a picture of the plunger installed for the front window switch rockers:

For comparison, here is a shot with a top and bottom rocker removed, you can see that the plunger is not present on the bottom:

Remove the plungers and their tension springs from the front switches of your donor switch assembly:

Remove the rear window switch rockers from the new switch panel, referred to as the "main" switch panel from here-on-out:

Install a spring in each hole on the main switch body:

And then the plunger:

Plungers installed:

Reinstall the rear switch rockers. Do this carefully. When complete, test the rear switch's range of motion and make sure that all positions engage properly:
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Opening The Switch Assembly

This is pretty straight-forward, but to make sure I cover all bases, I thought I'd touch on this. After the rockers are back in place (to prevent the plungers and springs from falling out and getting lost) we will want to remove the screws that hold the two halves together. There are seven T-6 Torx head screws on the rear. Remove them all:

Using your small flat screwdriver, gently separate the four locking tabs around the sides of the switch assembly:

Once all tabs are released, gently separate the halves, taking care to keep the rocker-side down:

Here is the bottom of the switch rockers. If you take this off in any position besides the rockers facing down, those white pieces you see will fall out everywhere:

Modifying PCB To Enable One-Touch Circuit

This part is tricky, to say the least. All the parts you need can be scavenged from your donor switches, including the two 768 ohm resistors. The catch is the resistors are not the easiest to remove from the circuit board. Because I already had a pre-modified switch PCB, I will not be covering that part here. However, I have clearly marked the donor and the main PCBs and show you exactly which components you must scavenge and where to install them.

Now that the two halves are separated and the half with the rockers and small actuating pieces is safely to the side, remove the PCB and membrane from the back half of the plastic case.

The trickiest part of this stage is removing the resistors from the donor. Pictures of this wouldn't have helped anyway. It involves gently unsoldering the resistors completely, and VERY GENTLY breaking them free from the board with needle-nose pliers. I can't stress how gently you must handle the resistors, they are glued, as well as soldered, to the board which is why they are so difficult to remove. The glue is used to hold the components in place before soldering at the factory, in case you're wondering why they'd do something so asinine. There are bold textthree usable resistors on the donor, you need two. If you are unable to remove them from your donor board, you will need to source some elsewhere to finish the project. Don't bother with Radio Shack.

You need to scavenge two of these three resistors, test them with a multimeter after extraction to confirm they are not damaged:

Here is where they must be installed on the main board. This shot also shows you where the two jumpers need to be soldered in. Use any small piece of wire as a jumper:
J = Jumper, R = Resistor

Modifying the Membrane Pad

This is the most involved part, without a doubt. To wrap up the hardware aspect of this mod, the membrane pad must be modified to work with the new circuit. Here is why…

The center membranes on the front window switches are raised a few millimeters compared to the other membranes on the pad. You can see this in these pictures:

Front Window Membranes:

Rear Window Membranes:

Now, if you read the other information regarding this mod that's been posted, you will see that madelgado cut the conductive discs from his donor membrane and glued them over the existing membranes to add the required height to function. This is what I did the first time I modded my switches. This worked fine, but because of the way the front membranes are molded Vs. the rear membranes, this left the rear switches VERY FIRM and had an overall unpleasant feel. This time around, I took more drastic measures and actually excised the front window membrane segment and grafted it to my main membrane's rear window segment. The rear switch function works and feels 100% OEM with my method. MADELGADO'S METHOD IS LESS TIME CONSUMING, BUT MORE DIFFICULT TO GET JUST RIGHT. MY METHOD IS MORE TIME CONSUMING, BUT YIELDS A BETTER FINISHED PRODUCT. THAT IS THE ONLY DIFFERENCE, DO IT HOW YOU FEEL COMFORTABLE DOING IT.

Using the Xacto knife, cut the front window membrane segment from the DONOR Pad, leave plenty of excess on the ends:

Mark your main membrane pad above the rear membranes. Make sure you mark it close to the membranes, but don't get too close to the recessed cups that allow the membranes to move. We don't want to disturb those. I used the edge of the PCB to make the line:

Using your Xacto, take a deep breath and cut down the line on your main pad as straight as you can. Here is the main pad with the rear window segment removed, and the donor front window segment mocked up:

Place the main membrane over the PCB and line it up properly, then lay the donor segment over it covering the bottom contact pads on the PCB, also making sure it's aligned with the contacts properly:

Now, trim the excess from the donor portion so it fits against the top half of the main membrane pad:

Take your time on some final touch trimming, get the two pieces to fit as flush as possible, be very careful not to remove too much material which will create gaps:

Now to start bonding! While the two halves are sitting flush, apply small drops of super glue on each corner. A dab'll do ya'. Seriously. This is just to tack the two pieces together, do not try to glue them together on the circuit board, as the glue will bleed through and possibly destroy the PCB:

Allow a few moments for the drops to bond the corners, then carefully remove the pad from the PCB. Lay it on some paper, and carefully finish gluing the pieces together:

The pad will take several minutes to set up properly. Set it aside at this time. Go back to the rear window membrane segment that you trimmed from the main pad. Place it back over the PCB in its proper location, and using your Xacto, cut off the trailing edge of the segment that wraps around the back of the PCB:

Only after you are certain the glue has set, place your new membrane pad on the PCB. It should fit perfectly and cover all contacts properly:

As we did with the segment before, cut the excess off of the back of the membrane pad, flush with the PCB:

Flush cut:

Glue the trailing edge from the rear window segment to your new membrane pad, do this after removing the pad from the PCB again:

Almost done! By now, your membrane pad should be looking pretty spiffy, and an untrained eye may have a hard time telling you've even fiddled with it. We're not quire finished yet, however. The membrane pad will need a few minutes for that final trailing edge to set up. While that is happening, take the rear window membrane segment and place it over the new rear window segment that we've grafted in. You will notice that the original segment has a hole in it that we must accommodate. Use a Sharpie, and press it through the hole in the cut segment to mark the new grafted-in segment:

You'll now have a mark on your new pad in the proper location, this will come in handy in a few minutes:

After the glue has completely set, install the new membrane pad over the PCB, and then install the guts into the back half of the case. Like a glove!:

Using the dot we made and the size of the other holes as a guide, cut out a new hole around the dot to allow the case halves to join without interference:

Now it's time to reassemble the switch assembly. While holding the top rocker half upside down, line up the back half of the assembly and snap them back together. Make sure all four tabs lock properly, this is a sign that everything is fitting together flush and properly. Reinstall the seven T-6 Torx screws.

Hardware modification is now complete.

Changes to CCM

Today I made a little more of investigation about the 1C0 CCM and door modules... with and without success... I did not really found the bit for the folding mirrors and the FOB (which I am still looking for) but I found another couple of bits related with this suspended thread... I have named the new bits:

- AUTO-UP capability
- AUTO-DOWN capability

It is located in each door module, in particular, front doors have it active, while rear doors have it.... yeah! DISABLED

Ok, the nice part:

We have to modify two bits in the two rear modules, so the procedure is repeated twice but with different addresses.

- connect [to module address 46] with vds pro and login (19283)
- [serial] read address 16416 and take the first byte (decimal). For my passat it is 153.
- convert to binary: 10011001.
- set bits in bold to 1: 10011111, which is a decimal 159 in my case.
- [serial] write the new value to addresses: 16416, 16461 and 16506.

- repeat this for the right rear module.
- [serial] read address 20512 and take the first byte. It should be the same as before: in my case it was 153.
- to binary, change bolded 0s to 1s and to decimal again: 159 for me.
- [serial] write the new value to addresses: 20512, 20557 and 20602.

It is done!

This CCM thing is gonna kill my health and my passat's battery, hehe, but you don't know how big satisfaction is to find something stupid like this... I hope that you enjoy it. Please report feedback if you succeed!

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