Avensis Car Alarm Keeps Going Off

[Rhythic]

Hi

I'm driving a 1998 TOYOTA AVENSIS GS 5 DOOR HATCHBACK

When I bought my Avensis there was a problem with the key/fob. I can lock the whole car with the fob but I have to manually open it with the key as 'unlock' on the fob doesn't work. This hasn't been a problem until yesterday.

I locked the car with the fob but realised the back door wasn't fully locked and opened and shut it. I then locked the car again. When I came back to the car to manually open it with the key, the alarm went off as soon as I opened the door. The car alarm light is now on in the middle of the interior of the car next to the dashboard.

I'm still able to drive the car it's just incredibly annoying having to hear the alarm every single time I get in or out the car.

The alarm goes on for 20-30 seconds and then stops unless I press 'lock' on the key fob whilst outside the car, in which case the alarm stops but the alarm light still remains on and the car alarm starts again whenever I open the car door to get in or out the car. The red light stays on whilst the alarm is sounding and whilst the door remains open, even if I stop the alarm by pressing 'lock' on the fob. However, once the door are all shut, the alarm light flashes instead of just staying red (until I open the car door again).

This problem did happen once before but I managed to fix it by opening the car door, putting the key in the ignition (but not turning it on), then twisting the steering wheel all the way left until it wouldn't go any further, then turning the ignition on and releasing the steering wheel.

However I've tried this same approach about 10 times and it still hasn't worked.

Does anyone have any ideas how to fix this problem?