Alarm Problem

[52LAZ]

hi there

my sister is having problems with the alarm on her 2003/53 is200 le auto, it has just started going off randomly throughout the night and is getting worse, just wondering if anybody has experianced the same problems, any advice would be very helpfull to us, thanks in advance.

rich

[ChrisIS200SportTTE]

Yeah common problem this.

First thing to check is your Battery, if it's on it's way out it will set the alarm off if the voltage drops.

If the Battery is fine then it's most likely gonna be the interior sensor. Lexus will sort this with a new sensor for about £100 or the sensor can just be disconnected but then you may have issues with your insurance etc...

[52LAZ]

thanks for your quick response chris, yeah it had a new Battery 1 month ago, i think we will try to dissconnect it, i was thinking maybe the Battery in the fob might be low but dont know if that would cause the alarm to go off.

thanks

[ChrisIS200SportTTE]

It'll have nothing to do with the key fob mate. I bet it's the interior sensor if you have a new Battery.

You can lock the car up without arming the alarm. Lock all doors using the power lock button on the drivers side then get out and just lock the drivers door with the key. The car will be all locked up but the alarm will not be on :)

[52LAZ]

great stuff thanks for your help mate, ill keep you posted the locking the car up like that sounds a good solution until we get to the bottom of it,

thanks

[janet]

I had the same, internal sensor disconnected....no more sleeping with the keys on the bedside table!

[jomo]

Had the same problem, but if you lock the car with the fob by pressing the lock button twice it switches off the internal sensors, you will see that the indicators flash about 5 times, thats to tell you its double locked.

HTH...

[LexIS200Sport]

Before you resort to disconnecting the alarm sensors, it is worth disconnecting the Battery completely (both terminals) and leave it disconnected overnight.

My car had the exact same issue as yours, and disconnecting and reconnecting the Battery appears to have resolved the issue for me.

I know it sounds like a random solution, but it is easy and free to do so why not give it a shot ;)

[janet]

Good idea,

I did do that and I had a few weeks without the problem only for it to come back (twice) to haunt me!. Strangely, maybe coincidence, it only seemed to happen at night, in warm conditions....never got to the bottom of that, I was too fed up losing sleep and explaining to the neighbours.............

[52LAZ]

_{hi all}

_{she said she has entered some sort of sequence using the fob to dissarm the internal sensor, she locked it last night using just the one press on the remote fob because see said double locking made it go off (before she had disabled the sensor) and all is well, but no alarm, so its sort of sorted,}

_{janet, yes this only started happening to hers the last few nights randomly, but it was at night and warm? who knows.}

_{but thanks for all the replys and its sort of fixed enough she can live with it.}

[AlexM]

I have the same problem - how do you disconnect the sensor in the interior light casing. Can't seem to get cover off. Useful to know for changing the bulb too. Cheers.

[52LAZ]

hi mate.

i will ask her what sequence she put in and give ya an update.

thanks

[sedmund]

Hello, Any update? I am having the random alarm issue. :eerrrmm:

Guess I will have to disconnect the motion sensor.

[janet]

...think it's all there sedmund, by the way I did mention the sensor was disconnected to the insurance company, they were not concerned. (Must remember it's disconnected as it seems I will be selling my lovely sportcross soon...boo hoo !!!!)

[sedmund]

will have to disconnect the sensor tomorrow. I'll need to look into the dome light.