Car Alarms: Toyota Rav 4 car alarm reset procedure., toyota rav 4, carand

Question
I have a M reg Toyota Rav 4 which has an immobilser alarm.
I have had to replace the battery on the carand I am now having real problems with the alarm - the alarm just went off and would not stop - I would press the remote button and it would go off for a few seconds but the car is still immobilised and wouldn't start.   I was told upon ringing Toyota that you have to remove the earth lead put the key in the ignition turning it until just b4 it starts then wait half an hour
take the key out press the remote button which should re-set the alarm and then start the car - great this worked but now every time I stop the car the alarm goes off and the car is immobilised.  Sometimes it works after half an hour sometimes not - this is ridiculous - haven't got hours to wait while the alarm decides whether to reset itself or not - any suggestions would be much appreciated.   Thank you :)

Answer
Please describe the alarm sounds you hear. Is it
the car's own horn honking? Or is it a siren blarring?

Headlights, or parking lights.
Is there a flashing L.E.D. in the dash area?

I can better answer you if
I can determine exactly what we have here.

Let me know.

ALARMTEK
CARALARMMAN.COM