Horn blows when locking/unlocking doors on 2007 avalon

Is the key and switch a matched pair? There is a chip in the key (black plastic grip). It must communicate with the switch for the car to start ...
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the lock unlock regulator fails to work of that particular window or some linkage system derailed

Hold both lock/unlock buttons on remote until horn sonds.

Did you try starting the truck?

Have you locked and unlocked the driver door with the key ?

sounds like a weak battery make sure u are getting 12 volts or better from the alternator

Try unhooking your battery for about ten mins. This might reset your security system. You might also try locking all the doors and then unlocking with the key.

1) Check the battery, or replace the battery in the keyless remote transmitter 2) If battery is replace and still a no go, see if the power locks would open and close with the door lock/unlock switch in your car, and if they do, then your remote transmitter needs to be reporgram agian. If not then the power switch is damaged, or fuse blown. If transmitter needs reprogramming, please take it to your nearest dealship and they can do that for you, either free of charge or for a small fee.

Hi Guest,
If the horn is blowing in pulses,it is probably the anti-theft system. Connect the battery and either lock and unlock the doors with the remote or use the key to lock and unlock the drivers door. This should force it to reset. If this does not work,drop me a line and we can go further. Good luck,Chuck

If the fuel gauge is lowering as you drive,and the fuel is still in the tank,then I would gather that,the fuel gauge sending unit in the fuel tank is not working correctly,and needs to be replaced.Brake repair comes in replacing ,both front,and then both rear.The brake pads are purchased in sets,front set,and rear set.These sets service one axle.To inspect the brake pads,the brake pads will have a sensor,made of steel,that will move closer to the brake rotor as the brake pad has worn down.If the sensor(made of steel)touches the rotor,it will squeal.If it does this,it is time to change the brake pads.The sensor does not always work correctly,and will not squeal,or can not be heard.To look at the brake pads,to see if they are ready to be changed,there will be about a 1/8 inch of pad left,and it is time to do a brake job on that axle.Check both sides,left,and right wheels,if one side is worn more than the other,do the brake job.Removal of the brake pads is a good idea.This way,you can see if there is any cracking in the brake pad itself.This is to be done for the front,and the rear.The front brake pads will where out two,to three times compared to the rear.This would be normal.As respect to the horn sounding upon remote unlock,well,it should be operational,make sure the horn works,I hardly ever use mine,so I would think you would not either,but depending on where you live,right? So if it is not sounding upon key less remote,then The control box may have a bad circuit for that out put.Replacement of the control box might be the thing to do.To install the hardware to do this,would only take wire.Come off the actuator controlling the door lock on the drivers door,and go directly to the horn,you will get a short burst from the horn.The actuator in the door only requires one wire to unlock,and lock the door,this is all you need to sound the horn one time.The short beep beep,would require a delay relay to be installed. I hope this is what you needed as far as information,and if it was at all helpful,please let us know,thank you.