(a)You can connect the garage door receiver to your home computer and activate it via iPhone. There is an apps for that.
(b) You can replace the antenna with a longer piece of wire say one meter and install vertically.
(c) You can try moving the receiver per below:
"Researched garage door antennas and made every kind I could, but nothing worked. So I just removed the receiver board from garage door opener and extended it 12ft (used 2-wire 18ga) to exterior wall and drilled a small hole to stick antenna wire thru and siliconed it! Perfect. works 50ft now. cost=zero Could be fancy and add a 3.00 radio shack box or 1.00 electrical 4x4 box for the receiver board."

(d) You can get an extended antenna like:
"Chamberlain/Liftmaster offers an external antenna kit that can be attached to the existing antenna on the motor unit. Refer to Antenna Extender Kit Part Number 41A3504. You can download the instructions from their website. Requires installer to drill hole through Garage Wall and mount the antenna assembly on the outside of the wall directly above the Garage Door. Then thread a piece of RG-6 Coax from the Antenna to the wire antenna on the back of the Motor Unit. Ground shield to motor unit."

 

I am thinking if the Lexus transmitter is the problem (weak), a powerful antennae/receiver system might do the trick. I would try the easiest which is to use a longer wire for an antenna, say a meter long and mounted vertical. Or put the antenna outside.

 

A longer antenna may actually make the problem worse. The length of an antenna is based on the frequency (wavelength) of operation. It needs to be a multiple of 1/4 wavelength to take advantage of any gain (although this is more critical in transmitting than receiving). You won't damage anything by trying longer lengths but the results may not be what you are hoping for.

 

From the manual:

 

Im having the same problem with my 2010 RX. I cant even open it when im about to hit the garage door. i can close it once im inside but from the outside i can never open it.

 

It's just a matter of getting the transmitter specification for the Lexus RX350 and find the effective range of operation if the line of sight is unimpeded. The OP already have his original transmitter replaced but still won't work. I would just try another transmitter and be done with it.

As for the length of the antennae, we can huff and puff until we are blue from talking and writing here. Just get a piece of wire and put it on and try. It takes 5 minutes.

 

I had the same problem with my 2010 XLE Camry. I took some cat 5 wire and made a new high gain antenna with it . I could open the other two doors ok but the third one was hit or miss. This was a hit have not had a problem with it now.

 

The garage door opener button does not work for me either (unless the vehicle is actually in the garage). For me i think the metal door is the issue. The regular button that came with the unit used to work down the street but now it only works if you're within 12 feet of the closed garage door. I might try option "d" suggested by LeoDLion, though i'm not sure if that would work with my garage door opener...i'll have to look into it.

 

My dealer is on the way over to my house with another 2010 to see how another vehicle will perform.

My dealer did tell me on the phone that they have a handful of customers with similar problem.

I will advise

 

the dealers 2010RX opened the door at about 50 feet (my RX was only working at about 20 feet).

They are ordering me a new overhead unit (motherboard and transmitters).

Even the dealers RX didnt come close to the distance I get with the original transmitters or the Honda.

I say bad design.

 

Yes! My specialty is Electric Power Systems although I was in management for the last 20 years. I retired at age 55 and just let my PE license go inactive since I don't practice anymore and can't see keeping up with the continuing PDH requirements just to be able to put PE after my name.

 

I have no problem with my 2011 RX. I can open my garage door (Craftsman) from one city street block away.

 

So installed an antenna extension kit to my garage door opener and it improved the range by about two feet for the regular remote...still no dice on the homelink. I used to be able to use the remote down the street (probably for the first year) but now i have to be right in front of the garage door to open it. I had hoped that the kit would improve things but it hardly did at all.

 

I have a 2006 IS and a 2010 RX and both work fine opening the community's front gates from at least 250', and my garage door from the street (75'). My door opener is an eight year old LiftMaster. It sounds like you just have a mismatch between the Lexus Homelink system and your Stanley door opener, I'm not sure you can do a lot about it.

 

What did you use to extent it with?