Factory alarm issues

Hi Everyone,

I am having issues with the factory alarm on my mother's 2001 Passat. It will start going off without provocation and it's starting to annoy her and her neighbors. At first I thought she was having troubles with the remote as she is getting older, but I have had the car at my house this week and it is sitting in my driveway right now trying to fend off an invisible burglar. The local dealer just tells me to make sure all the doors are locked because that will trigger the alarm if one door is not completely shut & locked.

The alarm will go off at any random time, and it seems to be getting worse in frequency. I have tried locking the car with the remote and also by using the key, and the only thing I have noticed is that sometimes (maybe once out of ten attempts) I will not hear the "armed" beep from the back of the car from both locking methods.

I have tried a search on the forum, but I didn't see anything similar to my problem. Any help or suggestions are greatly appreciated.

2001 Passat, 1.8T, Auto trans, 73,000 miles (and yes, all the doors lock & shut properly)

When you set the alarm does the car beep once and the red light come on? If it doesnt beep but the light comes on then one of the microswitches has failed (most common is trunk latch and driver side door).

It takes less than 5min with a vw scantool to access the computer and see what the last alarm set location was (ie driver door, pass door, hood) Once the faulty sensor is found, just needs to be replaced. The trunk latch is a fairly simple repair and the latch itsself is about 60-80 i believe.

When the alarm sets, it will beep only %50 of the time.

Thanks for the tip! I'm going to have the codes checked on Tuesday.