It may be the time to pay the piper.

The dome-light/door_ajar is a system input to the get into to lock mode (if you try to lock and the door is open you get a loooong beep). Visual feedback (from sensor to bulb-lit) says that part is working.

The receiver self test, confirms:
Your key is sending the signal
It is beeing received and understood. [another key would not solve your problem (imho)]

There may be more tests for each key button that would confirm which signal is being transmitted and understood.

Then the last item is once understood by the receiver, does it get sent to the lock(s), and why not.

Salim

 

Yeah, I'm thinking I may end up going to a Lexus dealership. I'm going to wait till my uncle get's back from vacation, and then take it to his shop and see what he can find. If he can't find the problem, I'll have to take it to the dealer. Hopefully not though, because they would surely charge me a ridiculous amount.

I feel like if anything like the body control module was at fault, then I would have more problems than the keyless entry not working.

Another thing, I noticed today was that when I press any button on the remote, I hear a very faint buzzing noise near the area under the steering wheel. Sounds like it's coming from behind it. It's like a buzz, but it's not very loud. I don't think I'll be record the noise, but I'll give it a shot. Is there anything related to the keyless entry down there, I know there's whole bunch load of wires. lol

 

I was looking at the C-Best settings:https://www.clublexus.com/forums/403505-post36.html
And, the first one is "Wireless Door Lock Remote Control Wireless operation", do you think it's possible it somehow is on "NO"?
Is there any way to check without going to the stealership? lol Or, is there a way to reset the C-Best settings? By removal of a fuse or something...

 

Hyper, you mentioned the buzzing coming from behind the steering wheel. There is a BCU in the left upper dash area and very close to it on the left is J/B5 (junction box #5) which looks like it has a number of relays in it. Each door lock would have a relay and I'm wondering if that isn't the relay box for the 5 doors and possibly something else that would use relays. The "buzzing" you heard is exactly what a relay sounds like when it's not getting enough amperage to actually operate the relay. aaaaaaaathere are many things that could be the problem but poor conection in any plug ins to the BCU or Relay junction box could be the problem. (BTW, don't EVER assume because a fuse "looks" good or that a plug contacts "look" good that the juice is actually getting through that contact, whatever kind it is). ALWAYS check with a DVM. It may not be a bad BCU, possibly a poor connection, and I have seen it many times. "Reset" fuses, relays and plug-ins by unplugging and replugging 3 or 4 times. A contact can "look" perfectly clean and still not be completeling the circuit it is in because of the low amperage that most of the circuits operate on today with everything going through relays. With direct power wiring that we used to have there was enough amperage to "power through" a connection where today it is MUCH easier to lose connection on a clean "looking" contact because of the very low amperage needed to operate a "signal wire" for a relay. This may not be your problem, but you can got absolutely nuts chasing a problem because everything "LOOKS" perfect. "LOOKS" can be decieving!

 

Thanks for the information Code58! I'll take off the panel, and look at the relays. And see if I can spot any loose wires. It may be awhile before I can do this, but I'll update the thread when I do. (lot's of work related stuff in the coming weeks, so I probably won't get around to doing it till March...boy do i hate work.lol)

 

Warning ... sharing a war story here ,,, skip if not interested.

Very true ,,, AND one needs to know how the DVM works. My (ex) neighbor was a HVAC expert and knew how to use the DVM. He had a boat trailer and the tail light was not turning on. DVM would tell him there is 12v at the bulb socket. Yet a tried and tested bulb would not turn on. I told him to test voltage with the bulb in-circuit and then he found out that there was almost no voltage. Problem was that the wire had a joint and was all rusted out. Since DVM provided almost infinite resistance, the rusted splice showed no drop. The right tool to debug for him would have been a real bulb load and not the DVM or he should have used the DVM properly. It was learning for him and an opportunity for me to help my neighbor.

Salim

 

Salim, What you say is quite true. I have a "short and open circuit finder system" (consists of a transmitter and reciever that isolates the problem and what type it is) that I use in a case such as that. I have seen wires deteriorate (corrode) inside of insulation and not show any bulging or other outward signs of that deterioration. That's the reason I have the "finder" or "sanity saver", I would call it. I have a half dozen DVM's but I prefer to use my "Power Probe III since it also has a volt meter built in and is able to check ground as well as introduce both hot and grnd. You are correct that under those circumstances, you need the load on the line to detect that problem with a DVM. If you could easily find the other end of the wire you could also check Ohms which would reveal it.

 

I've found the problem and it's now fixed!!!

The problem was with the rear hatch, the lock cylinder on the back hatch was frozen. Yesterday, I went to open the hatch and realized that it wasn't locking and when I inserted the key, the lock cylinder wouldn't move. So, I figured the system wasn't letting the RX arm itself because the rear hatch wasn't locking. I sprayed some silicon spray inside of the key hole, and then sprayed a little on the key tip. And, then very gently inserted the key, and pulled it out and put more spray and then tried pushing the key in again. After, doing this a few times, the key cylinder became unfrozen and freely returned to the center.

At this point, I was pleased because this meant I could lock my rear hatch. But, then I thought to myself this is probably why the keyless system isn't working. So, i pressed the lock button on my remote, and what do you know... It's *****in' works! hahah < sorry for the language I'm quite happy, I don't have to pay the stealership to fix my problem..haha

So, thanks everyone for all of your help. I just wish I had checked the basics first. Once again, thanks!
I forgot how nice it is to have keyless entry, especially when it's 15 degrees F outside with windchill. Much better than messing around with keys.