DIY: Trunk lid button for use with Easygo kit

[Chaetagnath]

Note: This DIY is written for those with an FRS or BRZ premium that has an Easygo push start/wireless entry kit installed.

One think I dislike about the Easygo kit is the trunk release button on the remote. It is slow, and usually takes a couple of tries before it finally pops the trunk. I have no idea why.

However, I no longer care, because I installed a button on the trunk lid, which allows me to pop the trunk manually (a standard feature on the BRZ limited, 10 series, and monograms I think).





This is something I have wanted to do for a while, and I finally figured out how to do it.

How it works: Assume you are walking up to the car with your keys in your pocket, and the car is locked. Press the trunk lid button once, and the doors unlock (just like they would using the button on the handle). Then, hold the trunk lid button down again and the trunk pops open. As long as the car is unlocked, the trunk lid button will pop the trunk. If the car is locked again, the trunk lid button will unlock the car, as long as the key fob is in range. If the key fob is not around, and the car is locked, pushing the key fob does nothing, so the car is secure.

The trick to this whole setup is using a DPDT (double pole double throw) bistable latching relay, which alternates between two positions. The latch relay stays in the same position until a trigger switches it over to the alternate position, even when power to the relay is interrupted. I got mine off of ebay for 20 bucks, just be sure you get a 12 volt one.

Here is a schematic of how it works




Basically, you tap the wires which control the lock and unlock, each is a positive pulse to the lock motor. So, when the car is unlocked, it sends a positive pulse to the latching relay, which switches it over to the trunk switch. When the car is locked (either by the remote, door handle, or switch inside the car), a positive pulse goes to the other side of the latching relay and the relay switched to the other position.

[IMG]<iframe width="560" height="315" src="https://www.youtube.com/embed/R4IJcu65JvM" frameborder="0" allowfullscreen></iframe>[/IMG]


Meanwhile, the latching relay swaps between tapping the trunk switch in your dash and tapping the door button which sends a signal to the easygo box. If the car is locked, and your key fob is not in range the easygo box receives a signal from the button, but does nothing. If the key fob IS in range, the easygo box outputs a signal in response to the button to unlock the doors, which sends a positive pulse to the latching relay switching it over to the trunk switch. Now, when you hold the button it will only pop the trunk. Locking the car sends a positive pulse to the latching relay, resetting it over to the door handle button, and so on.

Ok, so, if you want to do this mod, you will need the following:

An easygo kit installed on your car
A trunk lid button - part number: SU00302777
A DPDT latching relay, 12V: I could not find a vendor, but I found mine on ebay. Specifically I ordered this: RY2LS-UAC12V DPDT LATCH RELAY by IDEC
Lots of wire, preferably different colors, 18 gauge is likely fine
Soldering iron, heat gun, and shrink tubing
Bunch of zip ties
Dremel or something else to cut through plastic on your trunk
Time, patience, and something to drink

If you installed the easygo kit yourself, you likely can do this mod fairly easily, although it takes a few hours. If someone else did the install for you, you may want to get them to do it as well, because there is a bit of soldering wires involved, or you can give it a try yourself, just takes a bit of time.

Be sure to disconnect your battery before doing ANY electrical work on your car.

1. Install the trunk lid button
On your trunk lid, the part which your badge is attached to above the license plate is actually plastic, and comes off.



I recommend removing it (just a few nuts holding it in place), then you will need to cut a hole for the switch. Measure carefully, I marked it with pencil first, then carefully cut a hole with a dremel. You want to be conservative so that the switch fits tightly. I ended up cutting a hole which was slightly to small, then slowly expanded the cut until the switch just fit.




Once you have the switch installed, you can put this piece back, but first look for a rubber stopper on the trunk lid



Pop that thing out



Run the wires of the trunk lid switch through that hole (it comes with a rubber stopper which will fill that hole). Then reattach the plastic piece to your trunk lid. Now, you will need to solder two very long wires to the trunk switch and run those all the way to footwell area on the driver's side.

Now, the button is ready to be attached to the latching relay

2. Set up latching relay

I soldered short wires to each of the connectors on the latching relay, and then color coordinated each wire with shrink tubing (tape would likely work too). Trust me, it makes it a lot easier later on. Also, having two different wire colors to indicate positive and negative is a good idea too.



So on this particular relay (see the earlier diagram), it has 10 pins (1,4,5,8,9,10,11,12,13,14)

They should be connected as follows



Of course, the latching relay you get might end up being different, but this gives you the right guideline for setting it up.

You will need to remove the dash piece under the steering wheel, and the kick plate down by the driver's side left hand side to reach the connectors. Also, you can use taps, but ultimately they will fail, so I highly recommend soldering everything.

I then stashed the relay and all the wires under the dash with zip ties to make it nice and tidy.

This is one of my favorite things I've done to my FRS, it makes life so much easier.

Edit: It occurred to me today that this would work on cars without the easygo kit as well. You simply don't hook anything up to the connectors I used for the door handle. The difference in functionality would be that the button would only work when the car is unlocked. When locked the button doesn't open. The nice thing about combining with the easygo kit is that you can simply open the trunk when your key fob is in range without having to physically unlock it first.

[XtremeMaC]

wow I don't know how I missed this post.
Will give this a try. definitely a good idea that should have come with the vehicle...