door control module question

[henkjooste]

Hi all

All the windows on my B7 stopped working a couple of months ago, and it took me a while to trace the problem to a faulty door control module in the drivers door (it is a rhd audi)

I proceeded to order a new module that arrived yesterday, and it got fitted, and all the windows worked to my joy.... for about 10 minutes, then same problem, no windows.
It seems like something is damaging the pbc in the controllers... Once again I checked all the wiring and all is good, the voltage on the power going into the module reads at 12.5V with the ignition on and at 12.8V with the ignition off, does that seem right, and does anyone have some clues as to what would blow the new controller?

ANY help would be welcomed, I would rather set the damn thing on fire rather than going another 2 months without windows.

[mtroxel]

Tough one. I just went all through my digital Bentley (easier to search than paper Bentley) and cannot find a diagnostic on that module. Here's what I know. On a left hand drive it's module J386. Its driven by the comfort convenience module J393 under the carpet below the driver's seat (again, LHD). I can't find much on diagnosing that system at all. I would tell you that your voltages above are a bit weird. When you talk about "ignition on", do you mean just the key turned on? With the motor idling I get about 13.6....on most any car.

That said, is there some power conditioning going on in J393? Could a faulty J393 send voltage spikes to J386? I don't know. I assume the carpet is bone dry in the J393 location (under driver's seat on a LHD).

Have you confirmed that the door module is the problem or is there a chance you're getting intermittent voltage to that module?

[henkjooste]

Thanks for the reply, the module under the seat is dry, that was the 1st thing I checked, the voltage with ignition on, is without the engine running. I am pretty confident that there is power to that module in the door the whole time, by the looks of it, the central locking, and the alarm controls in the door connects to it as well, and that all work fine, its just the windows.
I have a buddy with the same Audi, but are a bit reluctant in trying his module in case it goes as well.
the part number I have for the door module is 8E2 959 802F

[henkjooste]

It seems like the relay on the board is dead, might be because the motor is trying to pull too much power from it. I am going to fit a bigger relay to the board and hope I don't set the car on fire

[mtroxel]

That makes some sense....that you're pulling too much power. Bad motor? Is the regulator mechanism bound up some way?

[henkjooste]

I suspect it is due to a bad motor. It could be from any one of the doors, as far as I can figure out, it looks like that one relay gives power to all the door motors. the regulator looks in perfect condition.

[mtroxel]

If that's true, couldn't you put a multi-meter between the ground and the ground terminal on the module and measure the amps while you operate each motor? In fact you might have some draw without operating a motor and it's a matter of disconnecting the other doors till you find the one where the idle draw drops to 0.

[henkjooste]

I will have to get another module 1st to test. The relay is apparently specific to that board, it is a 8pin omron relay with no alternatives, and in SA it has been discontinued, and I can import one for $41 from your valley.... which is about the same as importing a complete 2nd hand unit with shipping and import charges.

I got thinking, it could also be the auto function on the window that is causing it, maybe it does not stop on auto up, and then puts a serious amount of strain on the relay while is is trying to close the window?

I only thought of this seeing that the relay dies when the windows are up, never with the windows down.

[billyhoyle]

You checked the wires between the door and the body of the car?

[henkjooste]

I have checked the wiring, and it all looked ok, but I am going to take the whole harness out this weekend and test it again. I am now 100% sure that the wiring is the problem as the windows has suddenly started working again.... This car is seriously possessed.

[henkjooste]

Just an update, the windows is still working, so I dont think im going to mess around with it anymore while it is working. I will rip stuff apart as soon as it stops again.

[mtroxel]

Probably wiring since your dead module is suddenly alive. There is a chance its a flaky convenience control module since that provides power to the door modules.

[henkjooste]

Would the ccm not affect more things if it is on the way out? I might be wrong but I did rule it out due to the fact that all the other features controlled by it is working like the alarm and central locking. The windows is completely random today, one minute it works, next it does not.

[BenMTL]

Just an update, the windows is still working, so I dont think im going to mess around with it anymore while it is working. I will rip stuff apart as soon as it stops again.

Funny...Exact same issue I had last month. Out of curiosity, where did you buy the master window switch from and how much did it cost?

I bought mine from eBay, for like $20 USD. I was skeptical but a bunch of the B6 guys use it and swear by it so....My rear passenger window all of a sudden wouldn't go down 100% of the time (5/10 times only)...Even worse, it also affected the switch on the actual rear passenger door

How is that even possible? OEM switch is like $80 USD but it looks like it is the only option to fully resolve this issue...

[henkjooste]

Funny...Exact same issue I had last month. Out of curiosity, where did you buy the master window switch from and how much did it cost?

I bought mine from eBay, for like $20 USD. I was skeptical but a bunch of the B6 guys use it and swear by it so....My rear passenger window all of a sudden wouldn't go down 100% of the time (5/10 times only)...Even worse, it also affected the switch on the actual rear passenger door

How is that even possible? OEM switch is like $80 USD but it looks like it is the only option to fully resolve this issue...

I got mine on ebay as well, paid $42 including shipping to South Africa. If the windows on my B7 stops, it affects all the windows on all the switches. I did notice a pattern, if I close the driver side window and it startsjerking (like it is loosing power) then the windows will not work once the car is switched off, Leave it for a couple of hours, then it starts working again.

[BenMTL]

Sounds like we are talking about the same switch and the same problem.....For me however, it only affects my rear passenger window for some reason hahaha.

I am going to spend the cash however on an OEM part because what happened one time was, I put all my windows down just fine...But it was then about to rain soon and I couldn't put my rear passenger window back up on the master switch or on the door itself so I had to rush home before the rain 100% related to the switch because all my wiring is 100% dry and nothing else has changed except for the master switch. Still don't understand how a "corrupt" master switch can corrupt the individual switches on the doors themselves but obviously it can and you are not the only problem with this problem

[henkjooste]

I think manufacturers is over complicating things....

[mtroxel]

Would the ccm not affect more things if it is on the way out? I might be wrong but I did rule it out due to the fact that all the other features controlled by it is working like the alarm and central locking.

I don't know for sure. What I do know is that the windows and sunroof will work after you turn the car off, as long as you haven't opened a door. To me that means the CCM might be providing power to just that system, meaning there is some separation in there as to what gets power and what doesn't. So the fact that the power locks work doesn't necessarily mean the circuit that powers the windows is happy.

[henkjooste]

I don't know for sure. What I do know is that the windows and sunroof will work after you turn the car off, as long as you haven't opened a door. To me that means the CCM might be providing power to just that system, meaning there is some separation in there as to what gets power and what doesn't. So the fact that the power locks work doesn't necessarily mean the circuit that powers the windows is happy.

That does make sense. I guess I might have to start investing in a new ccm. Thanks for all the help so far

[mtroxel]

This thing's getting messy. I read your OP again. You said when the window doesn't work, you still have 12.5 volts at the door module. If you are certain of that, it's not the wiring to the door, or the CCM.

[henkjooste]

This thing's getting messy. I read your OP again. You said when the window doesn't work, you still have 12.5 volts at the door module. If you are certain of that, it's not the wiring to the door, or the CCM.

That is correct, still have 12.5V even if windows are not working.