Looking for tech advice on Gen 3 IV Powered windows

[Fatboy 18]

Hello, Can anyone advise.
My car is a GenII GTS, the windows only have two functions, Up or Down. On the later gen cars I believe that you have an added feature when you open the door the window drops down 1/2 inch so that it does not catch on the frame glass retaining clip and when you close your doors the window then moves up to the correct position. Is this controled by a separate module or is this controlled via your PCM?

I am trying to work out If it is possible to do this on a Gen II as I always have to push the glass slightly towards the car when closing the door to make sure the glass fits under the frame weatherstrip, its a PIA.

Thanks

[Steve M]

Hello, Can anyone advise.
My car is a GenII GTS, the windows only have two functions, Up or Down. On the later gen cars I believe that you have an added feature when you open the door the window drops down 1/2 inch so that it does not catch on the frame glass retaining clip and when you close your doors the window then moves up to the correct position. Is this controled by a separate module or is this controlled via your PCM?

I am trying to work out If it is possible to do this on a Gen II as I always have to push the glass slightly towards the car when closing the door to make sure the glass fits under the frame weatherstrip, its a PIA.

Thanks

The auto drop function is definitely controlled by something other than the PCM...maybe the BCM?

[viper04blk]

You could use an aftermarket security system key fob to control your windows.... wind them up and down with the fob

[Vprbite]

You could use an aftermarket security system key fob to control your windows.... wind them up and down with the fob

True you could do that. High end alarms should give you some options.

I thought it was in the regulator itself for us. Because one of the ways they break is not going down on door open or close but they will still go up or down with the switches. I could definitely be wrong about this, but I thought that.

[ACtechOPS]

Appears that all commands are routed through/generated by the BCM which uses relays to control the motor. Window motor has up/down/ground only.

[Fatboy 18]

Thanks for that ACthchOPS, So now wondering if there is a BCM for the Gen II GTS and could it be programed to work the window regulator, Or could a Gen 3 BCM be fitted to a Gen II and if it could where or what would it replace?
Knew this would be techinical, nothing's ever straight forward!

[FrgMstr]

My understanding that on Gen III and IV cars that the window drop is a function of the PCM. I was always told to make sure and not switch a Vert PCM with a Coupe PCM. No firsthand information here, but I am sure that is what I read.

[pony23]

I changed my vert to a coupe and the window drop function works fine. There seems to be no difference between the drop function of either body.

[Thom]

The gen 3 electronics uses three signals to determine/control automatic window drop.
1) A switch in the door handle signals door handle depressed (or not depressed.)
2) A switch (in the body, I think) signals door is FULLY closed (or not FULLY closed.)
3) A rotation signal from the window motor telling the gen3 electronics how many times the motor has rotated.

Using these signals, the gen3 electronics always knows how far up or down the window is, if the door is open or closed, and if someone is trying to open the door.

If the window is not all the way up, the gen3 electronics does nothing with the window when the door is opened and/or closed.

If the window is fully up, the gen3 electronics will slightly lower the window when the door handle is pressed. The gen3 electronics will keep the window low enough for the door to close until it senses tne door is fully closed, whereupon it raises the window to its former full up position.

Be aware that the gen3 door closed switch adjustment must be precise enough to only signal door closed when the door is FULLY closed.

Does your gen2 have a door handle switch?

Here's a possible simple solution to your gen2 window annoyance: Connect an electronic timer to your gen2 door closed switch and to your window up/down relay coils. When the electronic timer first senses the door just opened, it pulses the window down relay for a 1/4 second. When it first senses the door just closed, it pulses the window up relay for a 1/4 second.

[Fatboy 18]

Thank you Thom, That's just the sort of advice im looking for

[ACtechOPS]

Wiring diagrams here; https://www.dropbox.com/s/7osdvula7v...ZB-SM.pdf?dl=0

[Fatboy 18]

Thankyou

[sideways06]

Little bit of a thread hijack here but you guys seem to know a little about the window electronics...

I have had an issue where my drivers side window works 100% properly while the car is off. As soon as I start the engine the window will not go up/down reliably (it fails more often than not). It also does not lower when opening the door. If I turn the car off and turn the key forward (no engine start) again it goes back to normal and works every time until the car is started again.

I have replaced the regulator and it went in without any damage.

Do you think it might be related to a relay or maybe one of the door switches? I've never had the door not open when pressing the handle but I have had it not latch when closing. Maybe it is the door ajar switch you mentioned Thom?

Any ideas would be greatly appreciated.

[Thom]

Do you have a factory service manual? If not, get one.

Check the Body Control Module connectors (if memory serves, the BCM controls the windows) for loose connections. Engine vibration might be exacerbating a loose pin connection.

Start your engine, leave it running, and verify window problem is present. Without stopping the engine, try wiggling/jarring the ignition switch, then see if the window problem went away. (Oops, I forgot the gen 3 doesn't have an ignition start position. You can probably ignore this one.)

Another possibility is the charging system. The alternator is not running when the engine is stopped, so maybe the alternator/charging circuit is inducing the problem. Take the alternator drive belt off (or reroute a shorter drive belt so it skips the alternator) or unplug the alternator connectors, and start the engine. With engine running but the alternator not running or disconnected, see if the window problem is present.

Using your factory service manual, verify all engine grounding points have a good connection. Do.the same for body grounding points, especially those involved with the doors.

I'm not an expert, but these are some things I would look at and try.

[sideways06]

Thanks! I will give all of those a shot, great ideas.

[Vprbite]

I had a latch go that then messed up the regulator. Basically the latch wasn't able to tell the car (window, interior lights, etc) that it was properly opened or closed. The door sometimes woukdnt close. It would just bounce back. Perhaps something similar to that. Sounds like a communication error, IMO.

[sideways06]

I had a latch go that then messed up the regulator. Basically the latch wasn't able to tell the car (window, interior lights, etc) that it was properly opened or closed. The door sometimes woukdnt close. It would just bounce back. Perhaps something similar to that. Sounds like a communication error, IMO.

That is exactly what happens to me sometimes too. Do you know the part # you replaced? I looked up the door latch and came up with 4865727AC.

[Vprbite]

My ghetto fix was to cycle the ignition on and off and then it would work. I knew that wouldn't last too long though. I had my tech replace the unit. Give me a couple days and I can probably either get the paperwork or part number for you.