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Something that sort of bothers me about this "luxury" vehicle is that all four windows of the car don't have an auto-down/up feature; just the front windows. I've gotten used to having all-auto in my other vehicle that is by no means "luxury" so when I get in the wagon, I feel like a poor whenever I need to roll down the rear windows and must physically hold the switch down.
Every time I needed to roll down the rear windows like a common beggar, I'd look at the switches and be convinced there was a way to make the rear two function in auto. I'm rolling on a hunch that I could buy another driver-side window control panel and retrofit the front window switch modules into the rear positions. I mean, Honda is pretty slick about designing modularity into their parts bin so it shouldn't be a too difficult.
This is my story...
First things first, I needed to get a donor switch panel so off to the internets to find it. Checking with Acura fiche, we need the "SWITCH ASSY., POWER WINDOW MASTER", Part Number 35750-TL2-A12 and it's an affordable $230. Yeah, that's not going to work. The next stop was eBay and I found a few higher level assemblies of the master switch assy and the plastic trim panel from various 2nd gen TSX; any of them should work. None of them were reasonably priced. So I started thinking a little outside the box and pulled up some pictures of other Acura and Honda vehicles figuring that Honda-modularity might come into play again.
Sure enough, it looks like the master switch assy from a 2009-2013 Acura TL has the same general switch arrangement as the TSX, but the plastic trim panel is slightly different. Peeking at the Acura fiche, it carries a 35750-TK4-A01 part number so it's not 100% certain to be the same, but we'll try anyway. Hitting theBay again and was able to find a few parts for sale at more reasonable prices. Ended up buying one for about $30.
When it arrived, I did a side-to-side and aside from the plastic trim panels, the switch assemblies themselves appear identical when pulled out. I verified that the TL master switch assy fit in the TSX trim panel and vice-versa. Also plugged in the TL switch panel to the TSX and all of the switches functioned as they should: door locks, window lockout, front windows up/down/auto, rear windows up/down, all LEDs worked as they should.
So far so good! I'm excited. I'm not going to need to open the rear windows like an unwashed peasant for much longer- just need to crack the case open and swap out the switch modules!
So I got to cracking with my trusty mini-screwdriver and...
WTF is this shit?
Printed circuit boards? Nemesis! I can't do anything with this. I was expecting a plug-in switch module that I could just plug in. This is, like, not meant to be changed. Fun note: the little white plastic bits in the upper portion of the picture will fall out and scatter everywhere when you open the case. I didn't know that before hand. It increased the adventure significantly.
But I got to investigating the board traces and you can see the markings on the front window have two channels and have two contacts per channel. How that works is the rocker switch switch has two sets of contacts in parallel (so four copper points touching the board at a time) with two contacts always touching the "COM" pad in the middle of the trace. When the window is up and you rock the switch to the down position, you first hit a detent and the window starts to move down. At that ponit, the "COM" pad is being connected to the "MD" pad (see how it's longer- makes sense that it would activate first). Keep rocking the switch further and you click past the detent and then the second set of contacts bridge the pads between "COM" and "AD". The same thing goes for putting the window up: at detent, make contact between "COM" and "MU"; past detent make contact between "COM" and "AU".
So, applying intuition, that means to me that "COM" is common (ground), "AU/MU" is auto/manual up, and "AD/MD" is auto/manual down. Simple enough. Now, the interesting thing is that the rear windows have the same copper pad traces printed on them. So I posit that perhaps the function is already there and all we need to do is enable the pre/post detent capability on the rear switches. So, back to the plastic panel and pry out a front and rear switch. Looking at the back side of the plastic rocker, it's obvious that the front switches have a different molding than the rears- one that allows a detent stop before further motion. Next step: swap the front switch cover to the rear and see if it enables the auto down...
Nope. Shit.
But it's all there. Why not work? WHY?
So I poked around a little bit using a copper probe to bridge all the various pads and while I can make the front windows do what I want, it appears as if the rear windows are just meant to be manual only. I just can't get them to go auto-up/down which is very frustrating.
So, in summary, I wasn't able to unlock the all-auto feature of the windows. I don't know if it's possible but it's certainly smarter than I am. That and I don't really mess around with printed circuit boards; that stuff is just black magic. I wonder if it's a matter of not having the capacitors inline for the rear switches. But again, that's outside of my comfort zone so I call it impossible.
Sorry, this story doesn't have a happy ending but I did learn that the TL master switch assy will work for the TSX and presumably vice-versa so that opens up the future replacement options a little bit if necessary.
TL;DR:
Make Rear Windows Auto Up/Down? NO, failboat.
2009-2013 TL Power Window Master Switch Assy fits 2009-2014 TSX? YES, whoopidy-doo.
Waste a bunch of time and $30? OF COURSE.
This story was sponsored by: Swearing loudly and excessively.
I love your posts. Unfortunate ending to a wonderful adventure, but I enjoyed reading it and looking at the pictures. I know you didn't enjoy it but, thanks for posting this anyway! This would've been an awesome low-key mod. Damn PCBs... that surprised me too. But then again, I'm also sorta not surprised at the same time if that makes any sense
That's totally not what i expected to be in the switch module...
I hate the fact that they just didnt put all auto. I feel like a common peasant every time i have to hold the switch.
That's totally not what i expected to be in the switch module...
I hate the fact that they just didnt put all auto. I feel like a common peasant every time i have to hold the switch.
I know, right?
I figured each switch rocker would be a little plug in module that would swap to any position. That's what I've found in previous, older, Japanese cars.
It's a damn travesty.
Why does Honda forsake us? Make us struggle with window controls. My milquetoast fingers can't handle the excessive strain and the voice controls won't operate the windows.
I figured each switch rocker would be a little plug in module that would swap to any position. That's what I've found in previous, older, Japanese cars.
It's a damn travesty.
Why does Honda forsake us? Make us struggle with window controls. My milquetoast fingers can't handle the excessive strain and the voice controls won't operate the windows.
You know... that gives me an idea. wire the switches up to an arduino and then make a little android app which could voice control the windows...hmm..
Nah, unless there's some magic built into that module, all it does is allow you to remotely roll *up* the windows from the fob by double clicking the LOCK button.
Basically the opposite function that's baked into the stock fob when you double click the UNLOCK button to remotely roll *down* the windows.
It doesn't add any Auto-Down function to the rear window switches on the drivers master control unit.
Unless you can extract that magic, convert the remote double lock press into a single button press, add in the option for auto down, and attach it to the pins inside the module. Easy peasy!
To much words. TL;DR: The KP Tech module is designed to add capability to the signal received from the key fob buttons only.
Okay, I went and read up a little bit more about that module. There's little information on their website, but I think the installation instructions actually do a decent job of explaining what it's doing.
It plugs inline of the door lock circuit, allowing the lock/unlock function to remain as intended. It passes through (or doesn't touch, it wasn't clear to me) the unlock & hold to roll down windows function.
Where it adds capability is by intercepting the locking power circuit and adding the roll up function.
Normally, when you hit the unlock or lock button on your fob, the signal is wirelessly transmitted to the vehicle and it sends a 12V pulse to the door lock relay to open or close. When you click twice and hold the unlock button on the fob, the vehicle triggers the first unlock 12V pulse to unlock the door but then is followed by a constant 12V power which powers the window roll down circuit. I don't know how the window/lock control unit differentiates the signals, but that's irrelevant.
The KP Tech module adds that capability to the lock circuit to roll up the windows.
Where the whole thing falls down for the Auto Up/Down feature, and why we couldn't just find a way to add the Auto capability to the rear windows, is that the fob control is essentially just a momentary switch. We can see this by double pressing the unlock and having the windows roll down. They'll keep rolling until you release the button and once you release, the windows stop.
Basically, the same function as when you don't fully depress the window switch into the Auto position. The window starts to go down but stops when you release the button. Press it some more and it rolls more; release and it stops.
The real Auto functionality comes, I think, from the onboard capacitors in the window module. When the window switch is pressed passed the detent, it triggers the capacitor to discharge at a rate that energizes the circuit long enough to fully roll the window down. The KP Tech module doesn't seem to address this mechanism since it only works while you're holding the lock button on the fob. Once you release the button the window will stop mid travel.
But if you want the ability to remotely roll up the windows from the fob, the KP Tech module seems to do the job. Basically it adds the second half of the capability the key cylinder in the door has to the remote fob (twist to roll down/twist to roll up).
You could probably combine the circuits of the front and rear windows. Then you would would only touch the front window buttons to roll down both auto at the same time. Maybe?
If that works it would be cool to make a one touch button inside that rolled down all windows and popped the sunroof (I like mine popped instead of all the way open).
Last edited by opboarding; 05-19-2015 at 11:25 AM.
You could probably combine the circuits of the front and rear windows. Then you would would only touch the front window buttons to roll down both auto at the same time. Maybe?
If that works it would be cool to make a one touch button inside that rolled down all windows and popped the sunroof (I like mine popped instead of all the way open).
Hypothetically, if it were a matter of just adding a jumper to the circuit to connect the front window button to the rear, my uneducated guess is that the windows would only roll halfway down. I'm like 90% certain the "Auto" mechanism is the discharging of the capacitor on the board. Tying both circuits in together would (roughly) double the load and halve the motor run time.
Swapping the capacitor for one about twice the capacity would probably take care of that. Or it would cause the car to burst into flames. One of the two.
It's times like this that I think it would be nice to be more competent with electronics. I'm sure someone much smarter than me could look at the circuit diagram and figure out where to add a capacitor and diode to make it all work. Since the rear windows are the only ones that don't Auto, it wouldn't be much harder to add a button and circuit to trigger all the windows after that.
Hypothetically, if it were a matter of just adding a jumper to the circuit to connect the front window button to the rear, my uneducated guess is that the windows would only roll halfway down. I'm like 90% certain the "Auto" mechanism is the discharging of the capacitor on the board. Tying both circuits in together would (roughly) double the load and halve the motor run time.
Swapping the capacitor for one about twice the capacity would probably take care of that. Or it would cause the car to burst into flames. One of the two.
It's times like this that I think it would be nice to be more competent with electronics. I'm sure someone much smarter than me could look at the circuit diagram and figure out where to add a capacitor and diode to make it all work. Since the rear windows are the only ones that don't Auto, it wouldn't be much harder to add a button and circuit to trigger all the windows after that.
Farads! I can't be bothered with such tomfoolery...
The cap is about 1/2" in diameter, so a 1" diameter replacement should be right...
Please note, for future edification, that isn't the correct way to size a capacitor. Also, not even the correct way to double the size of a cylinder. Please don't noob it up.
I don't think the windows work like that with regards to the capacitor. A little bit of Googling leads me to believe that the window motor drives the windows up or down until it reaches a certain amperage(from physical load) until it hits the limit and then it shuts off. Kind of like a circuit breaker. It wouldn't have to do with time because you are able to auto up/down with the window half way up.
A concern I thought about is if the window travel between the front and rear isn't identical then you'll get it shutting off before both windows are all the way up/down leaving a gap.
Hmm. Good point. That should be easy-ish to check. Put the window down, Auto-Up it and grab the window to see if it'll stall.
Inherently, I don't like the idea of going to a hard stop like that to trigger a cutoff. But I suppose a timed motion would drive against the hard stop until timeout from any position that isn't full up or down.
Interesting.
I can't wait for the smart guy to chime in and point out how we're all over thinking it.
I just tried. Now I gots a handful of brain mush and am on the way to hopital ima ammalance.
No, really though, I did go try. And I think there might be an option 3. Here's what I did & observed:
1) Press window auto down switch: window goes all the way down.
2) Press window auto up, grab window and try to prevent it from going up.
- Motor obviously straining but didn't stop, kept pulling my hands up with the window
- Just when I was about to sissy out and let go, maybe 4 inches from the top, the window stopped and went back fully down.
3) Press window auto up: window starts going up.
- Grab window and it immediately stops and goes full down. Almost no force required to cause the action.
4) Press window auto up: window starts going up.
- Grab window and it immediately stops and goes full down. Almost no force required to cause the action.
- This is repeatable
5) Press window auto up: window goes all the way up
6) Press window auto down: window goes all the way down.
From here, steps 2 through 5 are repeatable.
So I could make a case both for and against it being A) timed, and/or B) amp loading.
I'm about to expose some of my obvious software background, so this might just be pure ignorance. This bit might also be irrelevant.
Anyway, from your steps and small sample size, it seems that #2 triggers some sort of a flag in the circuit. After the flag is triggered, all subsequent attempts to work against the motor (i.e., grabbing the window) will cause the window to auto-down with minimal force.
So what happens after step 5/6? If I try auto-up and grab the window again, will it require more force to cause the window to auto-down (i.e., the idea of the "flag" being reset), like in #2?
Exactly right. I probably wasn't too clear after step 6; what I meant was what you said.
I was able to "reset" the system by doing the Auto-Up and letting it go all the way closed without interrupting it.
Following the "reset" I was able to Auto-Down then Auto-Up and try to restrict the motion. It took much force and nearly shut before it stopped and went down. From there the "low force" trigger was enacted until it was "reset" by doing a full unrestricted Auto-Up.
Rinse and repeat.
Probably unimportant but this was all with the engine off, door closed, ignition to ON, and I never cycled the key while doing the test so it was one un-interrupted session.
You're saying the four switches on the drivers window control unit all do one touch control? Are all four switches labled "AUTO"? All the TSX controls I've seen so far only have Auto on the front windows and the Acura literature agrees.
Please prove me wrong though because that would be promising...
You're saying the four switches on the drivers window control unit all do one touch control? Are all four switches labled "AUTO"? All the TSX controls I've seen so far only have Auto on the front windows and the Acura literature agrees.
Please prove me wrong though because that would be promising...
Let me hurt you some more....... My rears are auto up too
i have never HAD the desire to roll down all windows at once.......
Yeah, it's not super critical, but much like adding the capability to turn on the fogligts without the headlights, it's a feature. My plebeian 4Runner does all 4 auto from the factory. But my "luxury" marque can't.
And once you start thinking about all the time you waste *holding* the switch down, well we're literally talking MINUTES of extra time you get back over the life of the vehicle. /sarcasm
05-08-2015, 11:55 AM
