Problem with immobilizer / alarm - car wont start!

[Libertine]

So I've had my car for a year now, not once have I ever heard the alarm go off on it, I just have a standard key with no alarm buttons on it.. apparently it has standard mr2 alarm ( mk2 rev 3 ) 1994 , although as stated I have never had the alarm go off..

I've just gone to open the doors on the car and the alarm went off, I put the key in the ignition and it stopped the alarm, however the car will just not fire up at all now.. I imagine the immobilizer is stuck on ? It's just as if the car is dead.. although there is a feint click noise when the key is turned located in the rear fuse box ( where a cusco brace would go )

Does anybody know how to fix this or what price I'm looking at to even get the thing sorted?

Thank you

[rtech95]

I just had same issue with factory alarm after battery died

Lock car with key on N/S and Unlock with key on O/S
Dont think it matters which side but that is what i did and worked fine

[n52]

Had the exact same issue with mine literally two days ago, except I have the remote unlocking. Have you done anything to the battery at all recently? Turned out some gunk had built up on my negative battery terminal. I tightened it right up and it all started working fine again.