I can open and close the tail gate of our 05 RX using the remote control or the dash button.

 

Thats an SUV with a hatch vs a trunk. I can close the hatch and both sliding doors in the Sedona from the cabin too.

Sounds silly, but they approach the engineering of a hatch and a trunk differently clearly.

 

Good to know. I thought certain models have that option.
When I tried to personalize our 17 ES I was told the trunk close option using the remote or dash button is not available on the ES.
My SA is not sure if it's available on the LS. I prefer to do it manually (push the button) for safety

 

No Lexus model I've ever seen has a power closing trunk you can close from inside the car.

 

I understand EU/rest of the world, have this option. The litigious US is another matter altogether...

 

any high end car audio shop should be able to follow my directions.. it's basically a 5 wire relay to the front switch using the trunk pin as the defining factor.. labor rates may vary depending on their familiarity with the car a few hrs..

 

How was the switch modified ?
Arvid

 

I just did mine !
- Get one of this http://www.ebay.com/itm/QTY1-CAR-REL...72.m2749.l2649 ( any five pin relay that has pin 85,86,30, 78, 78a )
- Wire it up just like this
30-in from front switch
87a- tap to the BLUE wire next the BLACK wire in the middle !
87- you need to run a piece of wire from this 87 all the way to the back of the trunk opener motor harness, its the blue wire from right to left ( see picture below )
- Power source you can tap from anything that has constant 12v + with those 85 and 86 wire on the relay.
I will try to take it part and take some pictures for you guys to see.

 

Here are some pictures for those who really want to do this !

 

great write up...

 

and a big Thanks to you sir !

 

Thank You both...my next modification ;-)
Arvid

 

I have this feature on my 2005 Toyota Sienna minivan. Same company, same feature. I have both an interior button for liftgate (open/close) and same on my keyfob. I love this feature, especially when needed in carpool line. Was also looking for the same mod for my future LS. But additionally it would be nice to have either a foot operated control or an auto liftgate with waving of your hand on emblem like on the RX. Likely coming soon (approx Mar 2018) by Vaistech although probably costly.

 

I appreciate that I found this subject with solution since I encountered the same problem need to solve.
I'm not a professional in electrical although I'm a engineer.
Regards to the abovementioned wiring of the relay, I have some queries and hope if anyone could advise me further.
1) if 85-86 was provided constant 12v, my understanding is 30 & 87 will normally close at all time. So, what's the purpose of 87a connect to the open trigger?
2) while 30 switched on, will it trigger both open (trigger by switch) and close (trigger by relay) at the same time and cause ECU malfunction?
I hope this old subject can still alert some professional to answer. Thanks in advance.

 

Professional is a stretch but it's not clear if you're trying to fix or devise something, this example from the internet is typically how one relay is wired and used but if a logic gate function is the goal you could probably do it with several relays.