I've been searching for this problem all over the place but haven't found anyone with this problem! Can someone point me in the right direction?

the problem,

Central locking has stopped working all together. The boot opens from the key fob thats it, and turn the key in the door and only works on that door

Get in car put the key in the ignition. The alarm sounds. But I can still start the car and move it. The alarm lasts around 30 seconds.

Can open the doors of the car as much as I like without the alarm going off. As soon as the bonnet or boot the alarm goes off again for 30 seconds.

I don't know how normal this is but my car has 2 alarm sounds the horn sound and a siren sound. It's only the horn sound when the alarm goes off with this fault!

Hope somebody can help!

 

you need to give us some more background before we can help...

do you have an aftermarket alarm? siren alarm sounds like it is aftermarket... and you still being able to drive the car whilst the alarm is still blaring also points to the fact that it is aftermarket and kill switch wasn't hooked up properly... OEM factory alarm is usually only tied to the horn sound if it is tripped...

has this always happened or it just recently started?

your central locking system not working may be a different issue (see the door lock actuator threads on how to fix/replace the motors...

you need to go under the dash and see if you can find an aftermarket alarm brain there... if indeed you do have an aftermarket alarm, there may be a short, (door/trunk/bonnet triggers fried) or the alarm brain is dying...

 

Thank you for your reply,

I'm going to have to dig around the car about the after market part as I'm not sure if honest. When the alarms gone off before (due to me opening the driver door when the central locking has locked the others) it's gone to the horn alarm and then shortly after a siren. This is a problem I've had since owning the car. But this time I only get the horn

This literally started happening today, never had the problem before. That's both the central locking and the alarm have both started this morning. Fiddled around the afternoon to no success.

 

look under the dash... depending on the installer, if there is an aftermarket alarm on the car, you can trace aftermarket wires coming from your ignition switch to a alarm box (brain)... if you see this, disconnect all harnesses to that box... and start testing to see if you still have issues...

do your central locks work when you hit your power door locks on the door panel inside your car? this will rule out whether or not your actuators are dead.

 

The central locking is not working at all from the button/key button or key in the door

I haven't been able to spend time under the dash yet as it hasn't stopped raining. But planning on doing that asap

Once again, thanks for your help!

 

If you have an aftermarket alarm there might be a toggle switch under your dash to disarm it. Put the key in the ignition and turn the key till all the dash lights up and that usual puts it in valet mode or disarms

 

I've hunted around, no aftermarket alarm on the car, it has 3 horns under the bonnet though? Car battery was completely drained this morning so I think the car must be thinking something is open. I am going to go with the doors as it's the only thing that won't set off the alarm when opened.and with the central locking packed up too. Checked all the fuses. Going to see what happens with the battery out of the car over night!

I hate electrics on cars! My audi a8 had so many electrical faults! Thought I'd get away with it with the old lexus haha!

 

Kam is right about having an aftermarket alarm.

I should have never added an aftermarket alarm on my car since the factory was fine as is. Mine was having that issue sort of, but the kill switch wouldn't allow me to turn the car on. Sounds like your kill switch is not working properly. I had to turn the key to the on position and leave it there and press and hold the valet button until the alarm turned off and then turn the engine on. Look for that button under the driver dash area.

 

****FIXED****

Battery problems is answer,

What threw me was that the car started and I drove it a short distance and had the same problem.

Basically the battery not giving out the correct output messed with the alarm. I'm not sure why it affected the central locking. But that now all works again. Apart from the driver door not locking but ill save that issue for another day..

As for having the siren and the horn... now it has a good battery the siren is working along side the horn alarm but no aftermarket alarm has been found. I'm going to put this down to UK GS's must have it? Theres no after market alarm on the car and I can not find the siren anywhere!

 

That's pretty weird, but at least it's fixed. Thanks for posting your resolution. Hope it helps other members with the same issue.

 

i know you resolved your issue. but please humor me on the below cause now im intrigued.

3 horns? can you take a picture? if it's truly just the horn, there should be 2 (low and high tone)... if the 3rd you see is actually a siren for the alarm, the only way to track it back to the alarm (aftermarket or OEM) would be to trace the wire itself...

won't be fun but you would have to trip the alarm and see which of the 3 horns are emitting what sound... then eliminate the two that do hi and low beeps. and that last one should lead you back to an alarm.

here is a dumb question that i should have asked from the beginning... what remote do you use to work the keyless entry? is it the one that is built into the key? or a separate remote? if it is the one that is on the key, it's either OEM or a factory add-on tied into the factory alarm... separate remote is always aftermarket on our cars...