Alarm Keeps Going Off, Early Hours Of The Morning.

Yates-Is200S · October 9, 2009

Hi all, right my alarm is really confusing me, and its causing many sleepless nights.

Basically, last night the alarm was going off every 20 minuites. it started around 3.00 am in the morning. waking the whole street.

it also did it the other night (again, early hours of the morning).

but it doesnt do it in the day? and also it doesnt do it every single night, but its getting more and more frequent.

what could this be ? and is it something that can be easily stopped? last night i had to slightly leave my door open so it couldnt self lock itself. which seemed to stop the problem but still this isnt really very safe.

has anyone else encountered this probelm?

janet · October 9, 2009

I had this earlier in the year (suggest search for thread), but only now and then....always at night.

In the end took the car to the dealer, and had them disconnect the internal sensor.......no problems since, and I am now not sleeping with the car keys next to the bed !!

TigerFish · October 9, 2009

Also worth checking that the Battery is in tip top condition. My GS used to do this if it hadn't been used for a few days and the Battery level started to drop.

Yates-Is200S · October 9, 2009

it had a brand new Battery a few weeks ago mate. if i had the interior sensors disarmed would it solve the problem?

wildybeast · October 9, 2009

may be wrong but i think lexus can alter the motion sensors sensitivity.

Yates-Is200S · October 9, 2009

how are the motion sensors turned down? is it just a switch or do they have to go through the ecu?

wildybeast · October 9, 2009

i think they have to hook it up to there computer.ime not 100% sure they can do it but ime sure ive heard it can be done.give them a call

Yates-Is200S · October 9, 2009

Just come off the phone to lexus and firstly he tried to say there is no fault with the is200 alarms and then i mentioned the about the interior sensors and he stuttered for ages and then he told me that there is a common problem with the interior roof sensors of the is200 and that it can earth out and cause the alarm to trigger. he then tried telling me i would need the whole roof stripping down and insulating all the wires including the roof that would need insulating. he said it would be a 7 hour job at £70 an hour, that amounts to nearly £500 pounds. which is a F***in joke! he also said it is the only way around the problem. i suggested turning the motion sensors off and he said no you cant because its apart of the ECU. ????

wildybeast · October 9, 2009

it maybe mentioned in the owners hand book (manual)

wildybeast · October 9, 2009

try another lexus dealer.cant see it bieng that much of a job.

TigerFish · October 9, 2009

it had a brand new battery a few weeks ago mate. if i had the interior sensors disarmed would it solve the problem?

But you've only had the car two weeks, with all the other issues you've had, I'm not convinced I would believe the previous owner about anything. Pop along to a Battery place and get it checked out anyway, the checks are free.

Yates-Is200S · October 9, 2009

hi mate, no u can tell its brand new, its immaculate, looks brand new, also the mechanic checked all the levels etc.. the Battery its working fine.

Yates-Is200S · October 9, 2009

ive just disconected the Battery for now so that the alarm doesnt keep going off, because its doing my head in.

plus im going abroad next week so i need to disconect the Battery for then anyway

Parthiban · October 9, 2009

You could just lock the car with the key until you get to the bottom of this instead of disconnecting the Battery everyday.

In any case, why don't you try just deactivating the interior sensors first and see if the alarm still goes off at night? At least that way you'd know whether it was in fact the interior sensors that were causing the problem in the first place.

micker35 · October 9, 2009

Hi Yates-Is200S,

I think, from reading previous posts about the IS200 alarm, that if you press the door lock button on the keyfob twice, this will deactivate the motion sensing part of the alarm. It's obviously not a solution but it's got to be better than disconnecting the alram.

Cheers,

mick.

Yates-Is200S · October 9, 2009

thanks for the replies.. how do i manually disconect the interior sensors? apart from using the fob, or do i have to use the fob regardless?

also if i lock the car manually with the key, does it not set the alarm?

Parthiban · October 9, 2009

thanks for the replies.. how do i manually disconect the interior sensors? apart from using the fob, or do i have to use the fob regardless?
also if i lock the car manually with the key, does it not set the alarm?

What year is your car? Yes if you lock using the key it doesn't set the alarm. It also doesn't operate the central locking, so make sure to lock the other doors with the interior button before you finally lock the drivers door with the key.

janet · October 9, 2009

I had mine done at lex Derby, you have to take down the roof lining to do it, they did it while I waited, eating biccies and drinking coffee. They charged me £47.50 plus VAT.

Yates-Is200S · October 9, 2009

hi all, just locked my car using the double click method. i sat in my car whilst i did it, and mooved around rather vigeriously and NO alarm went off... i then repeated the test with one click and the alarm went off..

so do you think this has solved it ? and do you think this is why it hasnt been going off every single night as i may have used the double click sometimes to lock it, not realising.

???

Yates-Is200S · October 9, 2009

p.s when i double locked it the indicators also flashed 5 times. (disabling the interior sensors i believe) ??

Parthiban · October 9, 2009

Yes the 5 flashes means the interior sensors are disabled. Best way to test it is to run it one week with the sensors on, and see how many times the alarm goes off, and then one week with the sensors off and see if it goes off - then you'll know for sure whether it's the interior sensors that are at fault or whether it's something else.