Previa Security Alarm

June 7, 2005

A query for you all on the security alarm for a 2003 Previa which I've just got.

The alarm keeps being triggered for no apparent reason. Also there is a symbol on the instrument panel which lights up (red outline of a vehicle with a key inside it). The symbol comes on after the key is taken out of the dashboard and continues to flash when the car is locked whether or not the alarm is set.

Unfortunately the user manual does not include an explanation for this symbol.

At the moment I have to leave the car with the alarm disabled.

Would appreciate any advice on this before I go to the dealer. I hope it is covered by the warranty if there is a fault.

Thanks

Tim

June 7, 2005

A query for you all on the security alarm for a 2003 Previa which I've just got.
The alarm keeps being triggered for no apparent reason. Also there is a symbol on the instrument panel which lights up (red outline of a vehicle with a key inside it). The symbol comes on after the key is taken out of the dashboard and continues to flash when the car is locked whether or not the alarm is set.
Unfortunately the user manual does not include an explanation for this symbol.
At the moment I have to leave the car with the alarm disabled.
Would appreciate any advice on this before I go to the dealer. I hope it is covered by the warranty if there is a fault.
Thanks
Tim
←

Hi mate, i had a similar problem when i got my previa, just had it fixed under warranty thou. Apparently, the Battery backup sirens power was being disrupted somewhere ie a wiring fault, anyways, the dealers replaced the full siren unit and its fine now. They can do a check on the system by doing a series of on off ignition turns and reading the LED display for the fault code.

The symbol youre refering to is the imobiliser. This means that when its lit, its active. This will light up when the key is removed as your key has a transponder in it, so when its removed, the system activates passively. Dont worry about this, its how it functions.

Note on warranty, apparently, by law, within the first month of buying a used vehicle, which ever dealer sold it to you is obligated to fix problem free of charge, then after that, the warranty takes over. I bought approved used toyota so either way im covered.

June 9, 2005

Thanks for that info. The dealer told me the same about the imobiliser and light so its just normal for the light to flash when the key is removed.

The dealer suggested that the alarm can be triggered by the dashboard "creaking" as it expands/contracts with changes in temperature so the sensor sensitivity needs adjusting.

Tim

June 9, 2005

did they tell you that after doing a diagnostic check using the LED> cos if they didnt, i would go back and ask them to check and see just whats setting it off, if it does correspond to the "dash creaking" then fair enough.

September 3, 2016

My alarm (factory fitted 2006 Previa) would keep going off randomly - problem was getting more frequent. Checked all the door switches and bonnet (easy) and boot (harder - you have to remove all the trim 1st!)

Found out how to disable the interior pressure sensor - which solved the problem:

'Single' lock the car (1 press on key fob = 1 flash), then double-lock the car (2nd press on key fob = 1 flash) then press and hold the lock button on the keyfob for a 3rd time - this time the direction indicators come on and stay on for a couple of seconds. Now the alarm is set but the interior sensors are disabled - it would still go off if you open the bonnet/door etc. but there are no more false alarms!

As an alternative you can completely disable the alarm (so it then won't go off when you open the bonnet/doors either) by leaving the bonnet open when you lock the car.
So to do this permanently, remove the bonnet switch from its bracket and lay it down out of the way in the engine compartment, then the alarm thinks the bonnet is (always) open when you look the car so the alarm won't arm!
To remove the bonnet switch, 1st remove the connector to it then you have to squeeze the two lugs holding the switch in its bracket so that the switch can come up through the bracket. Once its out you simly reconnect the connector and leave it laying down. (Or you could unbolt the bracket itself as then you can see more clearly what you have to do!!)