This is awesome, I don't even use my remotes cause it's so bad.
Mod: Extending range of keyless entry (1 Viewer)
- Thread starter Ayune
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- Thread starter
- #22
Simply extending the existing antenna(s) won't work well. Antennas work best if their length & shape are tuned to the desired frequency.
A random length of wire will poorly ‘receive’ many different frequencies likely drowning out the one you’re interested in. The correct antenna length & shape will resonate and ‘receive’ only around a certain frequency. In our case we want to listen to 315MHz which means a straight antenna length of 9.37” (measured from the PCB hole), or a coil just the right diameter, pitch, and wire gauge to resonate at 315MHz. That's what the OEM antennas are, as well as what's inside the new plastic antenna.
If you’re going through the trouble of gaining access to the box and soldering anything, it may as well be coax routed to a tuned antenna placed in the most optimal location. I did at first place the antenna on the A-pillar next to the grab handle and it didn't perform well, probably because of the body metal. The radio area was a short hop away and surrounded by pretty much just plastic. BTW the coax cable is not a part of the antenna itself, it’s just a very quiet conduit to pass the signal to the circuit board. It can be any length as long as its outer shield (braid) is connected to ground at the circuit board.
Sure, the main goal is to simply relocate the antenna higher up in the cabin away from metal that impedes the already weak signal from the keyfob. The OE coil antennas probably work really well, but sourcing the harness connectors & crimp terminals may be difficult and more expensive. Plus there's not a whole lot of room behind the radio for the whole box, which would need to be mounted vertically for the antennas to work well. It may fit above the glove box?
There's definitely some smarts inside the box. From what I can tell looking at the wiring diagram it talks to the Instrument ECU and would likely require re-programming if replaced.
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sleepycruiser
I will get by….I will survive -Touch of Grey LC200
- Thread starter
- #24
Gee, I don't know... I guess you could unplug the box and see if it starts before removing it entirely
sleepycruiser
I will get by….I will survive -Touch of Grey LC200
@Ayune I pulled mine out and it is slightly different than yours. You can see on your board where you scraped for the copper...I started to scrape mine in the same spot and realized it was just plastic. My copper areas are different. Does it matter which area of copper I solder the outside coax wires to? Below you will see the areas on mine...I have a screwdriver pointing to each. Thanks!
- Thread starter
- #26
Wow, glad you asked! Second pic is the grounded copper, with “C1” “C3” etc. printed over it. The “301” section is the antenna circuit, or center conductor of the coax.
sleepycruiser
I will get by….I will survive -Touch of Grey LC200
Haha. I started scraping and I thought that I should have hit copper....held it up to the light and I could see through the board on that spot. Doh!
Ok, so the center of the coax goes into either the Ant 1 or Ant 2 hole and the copper sheath (twister outside copper wire) that is tinned will go to the larger copper area where the screwdriver is pointed to in my bottom pic? So I should scrape next to C3/C4, etc....
sleepycruiser
I will get by….I will survive -Touch of Grey LC200
I hooked it back up and before running the wire to the radio area tested it out. I am able to unlock the doors, but they won’t lock with the fob. The panic button works as well. Any ideas?
Edit: I started the LC and turned it off and then tested it. All is working. And all I have to say is WOW. I walked up my driveway which is easily 50 feet and out of the line of sight and it was still able to lock/unlock. I will post some pics and other info tomorrow after I get the coax run and secured.
One thing I did notice is that the doors will lock automatically after about a minute or so. It didn’t do this before.
Edit: I started the LC and turned it off and then tested it. All is working. And all I have to say is WOW. I walked up my driveway which is easily 50 feet and out of the line of sight and it was still able to lock/unlock. I will post some pics and other info tomorrow after I get the coax run and secured.
One thing I did notice is that the doors will lock automatically after about a minute or so. It didn’t do this before.
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- Thread starter
- #29
Awesome! Glad to hear it’s working better. Yea, the auto-lock can be annoying, but it shouldn’t have changed from before unless it was turned off via techstream or something and now “reset” by unplugging the box. 
sleepycruiser
I will get by….I will survive -Touch of Grey LC200
What is the normal time for the doors to stay unlocked? Looks like I get about 30 seconds before they lock back.
- Thread starter
- #31
Mine is 30 seconds. I believe it read that in the manual too.
sleepycruiser
I will get by….I will survive -Touch of Grey LC200
Ok, so on my 2000...my board was different than @Ayune, but I scraped next to the C3/C4 and was able to get everything working. I haven’t tested the max distance, but will try tonight when I can see the lights lighting up.
You can see in the pic the bolt that needs to be taken out to get the orange box out. I tried the 10mm route and it wasn’t easy, so I did it with a long Phillips screwdriver. The angle was a little funny so I put the screwdriver into the Phillips head and pushed down a little and in so as not to strip the head. Worked well and pretty easy to get back in. I can’t imagine doing it with a ratchet....not much room.
The other pic shows where I mounted mine. For clarity, I ordered exactly what was in the first post from Digikey. Digikey shipped quick and everything was great.
If you are struggling with fob range this is well worth under $25 to do it.
Will report back on range.
You can see in the pic the bolt that needs to be taken out to get the orange box out. I tried the 10mm route and it wasn’t easy, so I did it with a long Phillips screwdriver. The angle was a little funny so I put the screwdriver into the Phillips head and pushed down a little and in so as not to strip the head. Worked well and pretty easy to get back in. I can’t imagine doing it with a ratchet....not much room.
The other pic shows where I mounted mine. For clarity, I ordered exactly what was in the first post from Digikey. Digikey shipped quick and everything was great.
If you are struggling with fob range this is well worth under $25 to do it.
Will report back on range.
- Thread starter
- #34
Awesome. The only suggestion I have is maybe moving the antenna up a bit so the shaft isn’t right next to the metal radio bracket. That may cause a slight “blind spot” toward the vehicle front. Test first and see if it’s an issue.
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sleepycruiser
I will get by….I will survive -Touch of Grey LC200
Will do. The bracket goes pretty far up and looks like it would be similar no matter if I moved it all the way up or left it as is.
That. Sounds. Awesome. I believe it was your amp bypass video that I really enjoyed watching.
Haha, I got a lot of comments on that video saying it was a huge waste of time to do it all that carefully with a connector. Guess I'm just a little loony like that. Might as well take that lunacy and turn it into a revenue stream!
While that may be true, it's also the right way to do things! I do my wife's Lexus projects to OEM quality... but my 21yo Landy... not so much lol.
In this particular case, I think a good harness makes a lot of sense though. While modding the box may not be too complicated as shown above, a harness would solve this issue for a lot more early 100 owners who may not otherwise dig into it. I had personally retired my remotes, and intended to just us the key cyl for the rest of time. Now that I see this thread, I'll be back in the remote game for summer!
- Thread starter
- #40
Yea, anything to raise those antennas higher in the cabin will help. Given their orientation on the circuit board the box should to be installed in a vertical orientation for best coverge.
