Alarm System

[Geoff5]

I have a 1999 Corolla liftback, 1.6 auto. Iv`e stopped using the central locking for the last two years now as the alarm began going off for no apparent reason, almost as if it was over sensitive. A couple of garages have looked at it without any luck and I decided to try again now though no local garages seem to be interested. The Toyota dealer are quoting silly money at £100 plus vat just to diagnose it but from what I have been hearing from people is that it could be something very simple such as a dirty boot latch, which Iv`e cleaned a bit or the black conical sensor at the back of the engine bay which might need adjusting when the bonnet comes into contact to it. I`m no mechanic but is there something I could do myself or is there something else I could consider?

Thanks

Geoff.

[FROSTYBALLS]

Moved to the Corolla club.

[flash22]

Factory alarm that sounds the horn ?

[oldcodger]

Hi,

Can you clarify.  if locking with the remote , does it sound the alarm straight away or some hours later ?

Equally if just locking the door with the key, does it ever cause the alarm ?

Not familar with your cars alarm circuitry, but would assume the boot, bonnet and door switches are just simple switches that are closed/shorted  when the bonnet/doors are closed.

If one is going faulty intermittently, then the simplest way is to disconnect one sensor at a time, and on the disconnected plug and cable, secuely fit some form of wire across the plugs two pins or sockets. 

The use the car as normal and see if the fault returns, if it does reconnect that sensor and try the next.

[Geoff5]

I`m getting it to a garage to diagnose and see what happens.

[Geoff5]

On 6/15/2020 at 4:35 PM, flash22 said:

Factory alarm that sounds the horn ?

Yep. Factory alarm.

[flash22]

Find where it tap's into lock/wires

a decent alarm fitter will be able to disable it, no problems

im sure there are diagrams on the net somewhere