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Discussion Starter #1
project: by-pass the Door Key Cylinder Switch, driver side door, with a simple electronic switch.

expected result: will roll up the windows, as if you had used the key in the dirvers side door. consult the owners manual for exact usage, but by turning your key one direction and holding for 5+seconds you can power up all windows while you lock your car.

please see the attached series of gif images for reference (i will post in series). i am guessing that a background in electronic switches, car electronics or simple know how and tinkering will be appropriate. a copy of the 2003-2004 350z service manual will be helpful (do a search for it on this forum site).

else, here is what i have found by doing some multimeter investigation:

there is, indeed, 5V running through the 'two' wires from the Cylinder Switch. depending on if the windows are down or up, the V drops to around 3V ish when the windows roll up or down by turning the key in the door. i'd like to know why it drops to 3V, but can sleep well with out knowing if it has nothing to do with by-passing the switch.

what i'd like to accomplish is a simple spst switch set somewhere between the Door Key Cylinder Switch and the next module over (the Power Window Main Switch) which will allow me to roll up the windows with out having the key in the cylinder, turned for 5 seconds in a direction.

this is required for the next step in the project, which is adding a relay to the spst switch for key fob remote control.

can anyone give me a hint as to where and what i might be looking to solve this?

domo!

fallen.
 

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From what it looks like to me is that the serial link to the power windows is looking for a falling edge for its signal. Once this happens I would think if the key is held, keeping the voltage at 3V probably considered 0, the serial link to the power windows still sees this low level signal (within the 200 ms range) and that is what activates the signal to roll down or up the windows depending on which pin is held at 0. I would have to see more schematics to be able to tell you how to wire up the door with relays. If you have more information about the door locks and windows let me know and I will look at it.

The reason it only drops to 3V is probably because that is a low enough signal for the computer to think that it is 0; basically seeing a change.
 

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Discussion Starter #9
I have some info that will help solve the Door Key Cylinder switch + windows control modules. In brief:

The windows are physically controlled by a type of motor reffered to as a servo. The ones that I got to play with a few days ago have the same kind of 'function' that the Z ones have. From the Service Manual, we see that the voltage along one of the wires from the primary CPU system is a square wave. In servo land, this is the 'white wire' which tells the servo where to turn- both in direction (clockwise, counter clockwise) and how far (think of it in terms of radians and the arc of the servo for clarity). The square wave is pulse formated, and can be changed to tell the servo where to stop. When you think about how the windows works, it becomes much more clear how the servo functions. Luckly, I have a class that is dabbling in servos this semester, and got to talk to the group on how I might control the window servo on the Z. Programing a chip to send the right signal to the servos requires a few tests in a physics lab that we have access to, and the cost to 'stamp' the chip and create the wireing leads is very cheap. Add to that a relay of your choice, set to the existing line from the CPU controller that the key fob uses to lock the doors, and you have the beginings of a cost effective way to roll the windows up on your Z with the key fob remote.

I've only just stumbled over this in class, so I'll keep researching the exact parts I would need to make such an add on. The best thing about it is being able to test the chip design in a lab to make sure it works before i drag the equipment home to test it on the Z.

Just an update, I'll get back to studying.

Fallen
 

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Aloha,
I like the door lock feature when the ignition is turned on. Going to install this after I finish the DEI Hornet 700 alarm, which uses the factory remote (documenting install for How-to Section). It's a "when I have time" project. The lady's interior looks like something torn it apart and pulled out the wiring!

A Hui Hou

PaulO
 

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Fallen,

You've made this WAY too hard on yourself.

You have completely over complicated the entire system.

The motors are nothing special, and have nothing to do with square waves. The motors are standard power window motors - reverse polarity (5 wire). At rest, both leads rest at ground. If you break the ground from ONE lead and apply 12VDC to it the motor will go in one way, if you break the OTHER wire and apply 12VDC to it the motors will go the opposite direction.

The square wave(s) are for different things, most importantly anti pinch. As the power window motor moves an encoder wheel spins. A digital pickup reads the pulses created by the wheel spinning (a square wave). The BCM has a preset value for a MINIMUM pulse speed (directly related to window speed). If the window is moving slower then programmed (i.e. the squarewave is too wide) the BCM will assume that there is something in the path of the windows.

The other [semi] square wave is the serial link between the power window module and the BCM. I'm not sure just why yet, but the power window module has a dedicated line to the BCM. The drivers side and the passengers side are tied together on one input. The modules send a signal of approximately 64 bits (1 bit per mil sec if I remember right). The power window modules send an 'ok' status under normal operation, and can send the key cylinder position, window button position, door lock switch position, and RAP on signal to the BCM [Although the RAP system is fed from the BCM so its kind of pointless]. I have mapped out all the bits and one of these days I am planning on playing around with them to see if it is possible to control the windows (up and down) by manipulating this serial link. because the relays to control the windows are IN the power window module I don't think it will work, but its worth a shot.

If you have any questions let me know,

Kevin Pierson
www.KPtechnologies.com
 
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