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Old 02-22-2011, 12:18 PM   #7
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Member#: 72730
Join Date: Oct 2004
Chapter/Region: NESIC
Location: Wayland, MA
2001 Lexus ES300,
2005 Outback XT


For those curious about the auto up/down and swapping switches around I have looked into this and can shed some light. I know some really want to believe that there is some magic combo of swapping switches around, so let me see if I can help.

Short answer: Forget it, ain't gonna happen. Get an aftermarket module.

Long answer: I haven't seen wiring diagrams or the switch for a 2011, but there are tons of Nissan/Infiniti models using the same type of switches so there is some existing hardware to have a good idea of how Subaru implemented this change. I got a cheap Infiniti M-somethign switch, and it was completely useless for the Subaru, so read on if you want to know why.

Back in the day I believe Subaru had auto up/down before most other manufacturers did. They did this the same way all the auto-down only windows worked, the same way that aftermarket "auto window" modules work. The switch completes a circuit, it is just connecting power or ground to the motor, then it "listens" for noise and resistance to indicate the motor has reached the end of its travel, then it "clicks" off.

The problem with this type of setup is that it needs to be "tuned" to the motor, and differences in resistance due to sticky windows in the cold vs easy sliding in the summer mean the "listening" needs to be pretty heavy-handed about not just clicking off when the windows is halfway down. This is fine for auto-down operation, but when used for auto-up the switch can't really tell if the window is just sticky because the grease on the tracks is cold, or the window is chewing through your children's fingers. I do believe that Subaru was sued over such a scenario, and as result they pulled the auto-up/down windows out of their cars.

Due to the above, NO car manufacturer uses auto-up windows without more robust pinch protection. The above method is still used for auto-down windows, presumably because the risk is so much less of pinching something valuable on the way down than it is on the way up. Subaru uses this method for their auto-down only windows.

What I described above is a very old method of powering a window, the switch completes the circuit when you press the switch down. Modern auto-up windows do not work that way. An auto-up/down window will have more than 2 wires going to the motor. In addition to power and ground, there are 2 more wires that carry a square wave signal for motion, or progress if you will, that feeds back to a window module, or a logic board in the switch itself. In the case of our Nissan type switches, the logic is in the switch.

What happens when you press the button on that full auto window switch? It is just a momentary connection on the logic board, even for the secondary auto position. The switch press becomes a "request" to a window controller, which then completes the circuit, and also starts listening to the motion input signal. If and when the motion of the window stops or slows too much, the controller will stop the window, or even back it off a bit, as the window logic is smart enough to keep track of how far the window normally travels, it knows if it might be munching on your children. In this way, winter or summer, the window can be closed with enough power to overcome any stickyness or account for wear on the tracks, but yet it will never take out your loved ones. Alarm installers call these new style window switches "data switches" for what should now be obvious reasons.

Note that since the travel has to be learned by the switch, sometimes when you disconnect your battery or at other random times the auto down/up might not work, the window has to be "re-learned" by putting it down and then up by holding the switch. This is fairly common with the Nissans, and now that it seems to happen with the Subaru, I think we can assume they are using the same logic to work the auto up/down window.

So what happens when you plug the new style switch into the old style windows? Nothing, because without the extra wires feeding the position/motion data, the logic board refuses to operate the window ;-)

So this is why you cannot just swap switches. Nevermind that Subaru may have moved terminal arrangement around as well. To do this for just the drivers window, you would need to get the motor and switch and do some custom wiring as well. Is that worth it to add auto-up to the just one window? I guess that is up to each person.

I know you might be thinking: What if you wanted just the old style auto-down on all windows, could you swap just those sort of switches in? Well first thing to know is the driver's "master" switch is one single unit with windows, door lock and window lock-out buttons. It is NOT separate switches. You would need to find a whole unit that does what you want. I searched and searched and came to the conclusion that Nissan is pretty much all "data" type switching now. Any of their cars with more than driver's auto-down will have auto-up as well, and you know what that means. Subaru is rather old school with their window wiring, you aren't going to find a swap there. I also looked for seperate auto-down switches for the passenger positions, and came up with nothing.

So there you have it. In the end I purchased 2 DEI 530T window modules and I have auto up/down all around. The aftermarket modules do use the old style "widowmaker" resistance/noise method. I don't have kids yet, and I only wired up my driver's door switch, so I have kept the risk low I think.

I have BTDT, if you think you can swap out switches and get auto stuff, FORGET IT, AIN'T GONNA HAPPEN!!
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