3rd Party Keyless Entry DIY (Why Not?)

[particlewave]

Yeah, I know...

I've had my car for 4 years and have never had keyless entry.
The best thing for the rest of you to do is to buy an OEM transmitter and have the dealer code the car, but I've put it off for 4 years because it wasn't worth the $300-$400 that the whole repair would cost. That, and you all know how I love to tinker, so...

I bought this unit off of eBay for $12. It is simply a series of relays that are controlled by the transmitter/receiver.

Set Kit Universal Car Remote Central Entry Lock Locking Safety | eBay

Below is the wiring diagram for the door lock mechanism. As noted in the photo, when you turn the key in the door lock, you are simply grounding either the lock or unlock wire, telling the immobilizer to arm/disarm.
Brown = ground.
Brown with White stripe = lock.
Brown with Red stripe = unlock.

What we want to do is tap into the lock and unlock wires so that we can remotely ground them, locking or unlocking the car. Tracing the wires back, they are easily accessible from the entry point right above the fuse box (remove fuse box cover by removing the 4 Philips screws).


The 3rd party unit uses remotely controlled relays to perform this same function (the cars system is safe since the 3rd party receiver is isolated and the relays just act like switches - same as the door lock).

This picture is a mess, but shows how simple the unit is. Basically, I just fed ground to both relays (by shorting them to ground) and when they are activated by the receiver, they switch the ground to the either of the 2 outputs.
The unit also has outputs for a flashing light to indicate when the car is successfully locked or unlocked (side marker lights?). I have not hooked these up yet, but fuses A3 and A4 (for the side markers) are right there, so will soon.
Lastly, it has relay outputs for a trunk actuator (both + and - ...I think ours is negative actuated, just like the door lock microswitches).

So, that's it!

4 wires; lock signal, unlock signal, 12V+ and ground (will add the trunk actuator and side marker flash later).
After finding the right wires, it took 20 minutes to install and now I have remote arming capability. Works just like OEM

Like I said, the best route is to go OEM, but I have time and am bored. This works great, though. Have not tested range, but works from at least 25 feet away so far. Also, the shape of the fob is just right to fit a crest on, so it will replace my leather keychain soon.

You guys can field the new guys that don't get my insanity

Video...

https://www.youtube.com/watch?v=Ghsv5X1UW4U&feature=youtu.be

[Hogosha]

Originally Posted by particlewave

Yeah, I know...

The best thing to do is to buy an OEM transmitter and have the dealer code the car, but I've put it off for 4 years because it wasn't worth the $300-$400 that the whole repair would cost. That, and you all know how I love to tinker, so...

I bought this unit off of eBay for $12. It is simply a series of relays that are controlled by the transmitter/receiver.

Stay tuned...more coming.

Staying tuned!

[rocartfe2]

I think one could reprogram the IC on the circuit board using a chip programmer and the code from your working remote but the little oscillator in the case I am not sure how to match that to the car. I only had to put new switches on mine to get it work.

[particlewave]

Video of me playing with it...

https://www.youtube.com/watch?v=Ghsv5X1UW4U&feature=youtu.be

[healthservices]

Lol I bought this, this week and was going to do it this weekend!!!!

[particlewave]

Originally Posted by healthservices

Lol I bought this, this week and was going to do it this weekend!!!!

Great minds!
The instructions are a bit wonky, but the install is pretty straightforward once you decipher the gibberish. Main points are that both receive a negative (ground) signal and don't get the lock/unlock wires reversed.

Before anyone asks, I didn't do step-by-step instructions because I figured that anyone with enough skill to do this would find what they needed in post #1.

If I can clear anything up, please ask!

[healthservices]

This is the one I got. I was going to do trunk and frunk too, but I figure I experiment first.

$14 eh, I figure I can play with it.

[healthservices]

Since I'm behind particlewave a day I may as well not fall behind any more. lol

I approach mine a little differently as most the items could be accessed under the drivers seat. besides after crawling under the dash yesterday to do the ignition switch I'm a little sore.




Be sure to unsnap the harness to the seat but keep it plugged in and wired as you do not want the Airbag light to come on after everything is put back together. You can only erase and reset the code if you have the proper hookup and not some generic unit. There is enough length in the harness to set the seat just outside the car.



For this door lock system, as they may be different for each system I think I only tapped 5 wires and grounded three wires...

for a total of eight wires connected.

Power- Red to I cheated and grabbed the lead to the immobilizer
Ground- black - to the existing ground lug shown in pic
Ground- yellow - to the existing ground lug shown in pic
Ground- yellow/black - to the existing ground lug shown in pic
Lock signal White wire - to small Brown/white on left side immobilizer
Opening signal- White/Black to small Brown/red on left side immobilizer
turn signal output - Brown wire to small Black/white wire on right side immobilizer
turn signal output - Brown wire to small Black/green wire on right side immobilizer




I just hooked up the door locks and the light output so I can see the turn signal light flash when the doors lock or unlock

Here it is installed...



here is my remote..

[healthservices]

As particlewave mentioned this system uses a neg ground for the signal. as you can see there are a couple of ways to configure the system...


This is the way I wired this product.

[healthservices]

So what was basically this ....




I cut the excess wires and this is what is left over to connect...



Notice I left the trunk wire in case I want to wire the trunk release at a later date.

Please note that these wires were for a 98 and your model year wire colors will vary

[Hogosha]

If we can get one of those, to work with one of these....
3 Buttons Remote Flip Folding Key Shell Case Replace for Porsche Cayenne 03 Up | eBay

That would be something!

[healthservices]

Originally Posted by Hogosha

If we can get one of those, to work with one of these....
3 Buttons Remote Flip Folding Key Shell Case Replace for Porsche Cayenne 03 Up | eBay

That would be something!

Thats funny, the one shell is more expensive than the remote door lock system!

I tell you though the Cayenne key is a monster. Wish i still had mine. but I had to carry the key by itself.

[Hogosha]

Originally Posted by healthservices

Thats funny, the one shell is more expensive than the remote door lock system!

I tell you though the Cayenne key is a monster. Wish i still had mine. but I had to carry the key by itself.

True, but only about a 10th of a real one.

[healthservices]

Just wondering how terribly expensive would it be to have a new circuit board made for a key fob like that though

Sent from my SM-T310 using Tapatalk

[particlewave]

Originally Posted by healthservices

Since I'm behind particlewave a day I may as well not fall behind any more. lol

I approach mine a little differently as most the items could be accessed under the drivers seat. besides after crawling under the dash yesterday to do the ignition switch I'm a little sore.

Very nice! I considered the same since all of the wiring needed is right there, but didn't want to have to take the seat out. I thought I read that it was a pain to get out, but I guess I should have looked in the Bentley.

Originally Posted by Hogosha

If we can get one of those, to work with one of these....
3 Buttons Remote Flip Folding Key Shell Case Replace for Porsche Cayenne 03 Up | eBay

That would be something!

Originally Posted by healthservices

Thats funny, the one shell is more expensive than the remote door lock system!

I tell you though the Cayenne key is a monster. Wish i still had mine. but I had to carry the key by itself.

I agree. I have a Cayenne flip key and ended up shelving it. It is far too bulky to have sticking out of the ignition and just feels awkward.

[Hogosha]

Well, it was only an idea!

[particlewave]

I love the flip key idea...jus feels wrong in the ignition.
Would be even nicer to incorporate the keyless entry electronics into it.

They look similar in size and shape to "healthservices" fobs.

[particlewave]

It's 4am and I was bored, so I moved the receiver next to the immobilizer, same as yours. I decided that I wanted the turn signal flash and the trunk opener, so went ahead and moved it.
The signal flash is definitely nice!

If only I could fix this darn insomnia...

[healthservices]

Cool! Is your box the later model style with electric trunk release or cable?

[particlewave]

It has the cable pull levers, but I did verify today that it has the rear trunk actuator. I think I'll leave it be for now. I seriously doubt I'd ever use it, but nice to know its there if I change my mind.