Just started having a weird issue with my 2006 TL. The alarm is going off, showing the right rear door as being open. The car was parked outside and there was a bit of rain today, never happened before.

I disarmed the alarm and pulled the car inside the garage, cleaned around the door sensor and made sure the door is closed but the yellow light still came on.

With the car stationary, I started it and sat in the drivers seat, the yellow light for the right rear door kept coming on then went away after a few minutes and then came on again.

My neighbors have been complaining because of the alarm, Im not sure what to do - can anyone help out with some suggestions on whether i need a new sensor or something?

And in the meantime, how can I stop the damn alarm from coming on - if I leave the keys in the ignition in the off position with the door closed, will that stop the alarm from arming and going off in the middle of the night???

 

Not sure about the sensor replacement, but there is definitely an open circuit. In terms of not having the alarm go off, it won't set if you leave the car unlocked. If you have a garage that is a viable option until youngest this resolved.

 

Sweet. Im pulling it back in the garage and leaving the key in the ignition for the night.

Hopefully that will keep it from going off, my neighbor is a real piece of work and wont think twice about banging on my door in the middle of the night if the alarm goes off again..

When you say open circuit - are we talking wiring or just a replacement sensor to fix this?

 

You needn't leave your keys in the ignition. Just don't lock the car. The alarm is armed when the red LED light on the drivers door flashes (approx once every 8'seconds). If you don't lock the car it won't arm.

Open circuit - is exactly that and unfortunately you will have to troubleshoot to find out.

I also found this from a the July 2007 TSB-

Security System Sounds by Itself
Currently Applies To: ’04–07 TLs
Got a vehicle in your shop with a security system that sounds by itself? Check the connectors behind the driver’s under-dash fuse box for moisture or corrosion. If the fuse box is wet or it’s got water damage, track down the source of the leak, fix the leak, then replace the fuse box.

 

Thanks! So far the alarm hasnt gone off but I left the keys in the ignition, will remove the keys now although I thought the tl auto locks itself if the keys are not inserted...

I was hoping this would be something i coulf fix myself, the dealer will charge 120 just to diagnose - which is a rip off.

 

The only auto locking I'm aware of is if you unlock the car with the key fob and don't open one of the doors with something like 20 seconds it auto locks and sets the alarm. Again all I am aware of.......

As an aside and if it helps there are 8 sensors that trigger the alarm -
One each on the four doors
One on the hood
One one the trunk
One on the radio
One on the ignition.

 

^ Cheers, and thanks for the help!

So last night the alarm didnt go off after I left it unlocked. I picked up a new door sensor from the dealer for 15 bucks and I just put it in - have been locking and unlocking for about 4 hours so far and it seems to work okay - ofcourse this was a cheap fix to see if it resolved the issue - if the issue comes back then Ill definately have it diagnosed from the dealer - for now though, fingers crossed!

 

Sounds good and maybe you are all set -

 

You could have manually locked the doors. Locking with the key fob is what initiates the alarm. But... sounds like you already fixed it.

 

Manually meaning either pushing the driver's door lock button down or using the power lock switch. Using the key in the driver's door or the key fob itself will set the alarm.