RX450hLhun

I've just tested the factory fitted theft alarm in my RX2020. It seems to make alert only if somebody opens some door from inside (I've tested it with my son, who left in the car after closing). In this case the alarm turns on: the outside horn honks, turn signal flashes, and there is a classic style alarm sound signal inside the car as well. But my problem is: if my son moves only in the car (w/o door opening), there isn't any alert. I've tried to left open a window, and flail with my hand inside the car, nothing happens. It seems, that the alarm system doesn't have an ultrasonic antitheft protection for indoors. As I know, the theft-turn-off button (near reading lights) should turn off the inside ultrasonic protection, so it should be exist. Strange. Other thing, if I close the door with double touch, then the inside handles will be inactive, in this case my son was not able to open the doors from inside, and consequently there was not any alarm... So the alarm seems to be a little bit useless. Does anybody have some experience about this?

Cocal

Things may be different in Europe/Hungary, but here the anti theft is to prevent people from getting into the vehicle and not from exiting from it. Also we don't have a button to turn the system on - off it's on automatically as soon as you lock the car either with the FOB or by touching the handle. The other thing, how close was the FOB to the vehicle, this may have something to do with the alarm action.

RX450hLhun

It's some misunderstanding here: the anti-theft is to prevent getting into the car, of course! The exiting was only a test. The inner door handle is locked to prevent getting into the car, if somebody break a window and tries to open the door with inner handle. And this function is not automatically: normally the inner door handles remain working. They can be disabled only if you close twice the door, with double push of remote key button or touching twice the outdoor handle.

Cocal

If someone brakes a window the alarm will go off immediately. And everything will be locked and the engine will not start.
Everything must start on the outside of the car for the alarm to go off. If one enters it with the FOB/Key I don't see how an alarm would be activated once inside

RX450hLhun

Are you sure, if someone brakes a window the alarm will go off immediately? Why do you think that? How does the car detect the window breaking itself?

Cocal

This is what I was told, when I got my 2017 RX350, there are some alarms that even warn you if you get within 1 metre of the vehicle.
There are sensors to feel the movement. I know of no alarm that will activate from the inside, all alarms that I know of are to prevent illegal entry and not illegal exit

RX450hLhun

OK, it's clear. But these are 2 different things: the prevent of "illegal exit" is a mechanic safety system, which can be activated with the double closing process. And the alarm system is an other thing: that is an electrical warning and anti-theft system. I've even got a button next to the driver's reading lamp (at sunroof), which I can temporarly deactivate the inner protection system with (= moving detector disable), in order to prevent unexpected triggering of alarm. For example, if I leave a dog in the car or I leave some windows open. Otherwise the dog or open window could trigger an undesirable alarm. I've tried to test this system, similar way, I could test similar systems in other cars. But it seems to be useless in this car, perheps there isn't any interior sensor.
But I've just found an older thread here on clublexus site (What is this Button -RX400H). This thread was for RX 3rd gen, but it has clarified, that this button is for only the EU and AUS market, and not for the US. Probably the situation is the same for RX 4th gen, and US owners don't have this...

Cocal

Yes that's probably so, some makes (Nissan, Kia etc) are now advertising of an alarm that will beep if one locks the car while there is someone/something on the back seat.

RX450hLhun

Problem solved! Better said, it wasn't any problem at all. :-) The anti-theft alarm system works well, even its ultrasonic part is OK. But our test was done on a wrong way.
We'd waiting too short time after locking the doors. Cca. 20 sec. after locking, the red alarm warning LED (next to the radio panel) starts flashing, BUT this time the inner moving detector is not armed yet. It starts to work only after cca. 1 min. One can test it easily, when one leaves a window open, closes the doors, and after 1 min tries to reach inside the car with his arm. The ultrasonic sensor detects the moving, and the alarm system will be working: outside horn honks, turn signal flashes. And with the button next to the driver's reading lamp (at sunroof) this ultrasonic sensor can be temporarly deactivated. Everything works fine.

Cocal

Glad you got it solved !!