Passat B4 Window Regulator: Automatic Up?

Hello everyone, I'm having a small problem. The power window on the passenger side of my Passat B4 TDI, manufactured in 1994, occasionally lowers itself - especially when starting the engine.
After doing some research, I've figured out that the problem likely lies with the electronics of the lifter.

I still have some electronics from a rear door handle. The motors are different from the ones in the front.

Does anyone happen to know if the electronics are the same for all 4 power windows? The electronics are only connected to the motor. Can the electronics be replaced without removing the power window motor?

Thank you very much for your help!!

I highly doubt the electronics are the same... However, the plug definitely fits.
You can't just install a control unit from the front or back. Unfortunately, it doesn't fit because the drive system operates with a cable at the rear and with a gear/linkage system at the front.
Hast du ein ele. Sunroof?
If I were you, I would check the wiring. The problem could also be caused by a broken cable or a poor connection (e.g., in the doors). Unfortunately, you'll have to check all four lifters and the sunroof, because the control units are connected to each other.
(Unfortunately, the control units in the B4 model are not diagnosable.)

I once had a similar problem. In my case, the sunroof would always open. The issue was with the control unit for the front left window.

Hab ein el. Sunroof.
According to the wiring diagram, the control units in the front and rear might be the same. However, it's difficult to be certain without physically removing them.
The control units are plugged into the motor. Doesn't it matter whether the motor operates via a cable or a scissor mechanism?
Well, I'll probably have to disassemble the passenger-side door at some point to get any further - I'll figure it out as I go.
Does anyone else know anything about this?

The control units are plugged onto the engine. Isn't it the same whether the engine operates with a cable or a scissor mechanism, or?


Unfortunately, that's incorrect. The motor is screwed onto the control unit. Inside the control unit's housing, there's also a kind of gearbox...

Take a look at eBay. Sometimes you can find window lifters for the 35i there. Just compare the pictures, and you'll see that they look completely different...

You are right!!

My description only applies to the rear lifters. I looked at a picture, and the entire housing is different in the front.
@DocSyndor, could you tell me how you approached troubleshooting the sunroof issue?
It's not necessary for me to have to take out all the engines now.
I can't imagine a broken cable, because the thing goes down regardless of the door position and always when you start the engine.
Thank you for your reply.

It was quite a hassle because you can't access anything easily. You have to remove the door panel and peel off the protective film (make sure to warm up the adhesive beforehand).
I would do it this way: Remove the trim panel of the passenger door and plug in the spare control unit from the back. The connector should fit. If that works (you'll hear if the motor turns when you press a switch), leave it plugged in for a while and see if the error reappears, i.e., if the window motor runs when starting the car. Otherwise, you'll probably have to check all the wiring and switches. If you're unlucky, the problem might be in another window regulator control unit, because, as I said, they are all 'connected' to each other (comfort function).

Very good idea.
If the weather is bearable this weekend, I'll try it out.
However, this assumes that the internal components, specifically the electronics, are the same.
Thank you for the tip .

In the Volkswagen Golf 3, the rear window motor designs are also different from the front ones. They only differ in the way the cable is routed.

BUT: You can actually unscrew this guide and replace it with the one from the front. I've already done it myself.


Perhaps it's the same with the B4.

Hello,

'The problem I was having with the self-opening electric door handle hasn't really occurred in the past week. So, it's probably not worth spending a lot of time troubleshooting it; it's better to wait and see if it gets worse again.'
I'll post again when I have some news!
On the Passat B4, the front hood operates with a scissor mechanism, while the rear hood operates with a cable system. The hood latches are attached to each engine type – they are plugged in at the rear and screwed on at the front.
I can't remove the circuit board from the rear control unit because the connector is encased in the housing. I'm not sure about the front one.
I also don't know exactly what's happening inside the circuit board; that would be quite interesting to know.