Help!! - Dealer cannot fix the problem??

[Jerry Scott[CO]]

Check your hood switch to make sure that it is adjusted correctly. If not, it could be tripping the alarm with vibration of the hood. Also check the rear hatch switch if you have a GTS.
Jerry Scott[CO]

 

[Ulysses]

There seems to have been a few early problems with the security system on the 2000's. (early meaning within the first 1000 miles). Especially on hot days. When mine did that, I had to use the key switch in the glove box. I turned it off, then turned it on after a few seconds. Then I reset the alarm with the key fob. Instructions are on the fob. That took care of it. It has only done it once more since then and I went through the same procedure to get it to work again.

 

[Joseph Houss]

As silly as this might sound, is it possible that your key fob is malfunctioning and sending the "lock" message to your car? If you haven't tried this, try taking the battery out of the fob (after the car is unlocked) and see if the problem goes away.