Rav 4 Alarm Problem

[KJonno40]

Can anyone help me!!! I have a Rav4 (2002)My alarm is going off every 2hrs (to the minute), sounding for a few seconds then resetting. I have checked all windows and doors but all seem Ok. Any ideas please?

[IanXT4]

Problems like this can be very difficult to diagnose at a distance.

First some basic checks.

1) Do you have any after-market accessories connected to the car electrics, Phone, IPOD or TomTom charger non standard radio etc etc?

If so remove/disconnect them all. It's feasible a charger could be triggered by say a TomTom’s internal charge circuitry to top up the Battery, cause a voltage spike and trigger the alarm.

(However as explained below it would not explain the very short alarm sounding)

2) Change the batteries in all the remotes, some alarms have a panic feature which maybe ? (long shot) is being triggered by a low Battery in a remote.

3) Does this happen when you leave the car at home or anywhere ?

(This is highly unlikely, but it happens at just one location it may be that an some external source, local radio ham,new cellular mast, etc may be causing a problem)

The fact the alarm is going off at regular intervals is I think is very significant. (To me it feels like a timing/charging circuit somewhere tripping in?)

Also very interesting is the fact that alarm only sounds for a few seconds (do you mean a few, as in under 10 ?)

If something was causing the alarm to trigger every two hours, I would expect it to sound for the full period ie 30 seconds at least. If the alarm is not sounding for the normal period I would tend to suspect an alarm problem.

(unless it was some form of panic alarm being triggered?)

Some ideas

You could try disconnecting the Car Battery for a minute and seeing if this resets anything.

Some Toyota alarms are fitted with internal rechargeable cells to power them if a thief disconnects the battery. I have long suspected that as these alarms get old the nicad batteries will age and to lose their ability to hold charge, even becoming low voltage (as one or more battery cells goes bad). This can lead to erratic behaviour, as used to happen in the days when "after market" alarms were fitted. I don't know of any way to check this out without taking the alarm apart and checking the internal battery with a meter.

In summary, if you draw a blank with the accessories and the alarm continues to trigger every two hours for a very short time (under ten secs) I suspect that the alarm (or possibly one of its sensors) has an internal problem. This probably means a trip to the dealer unless you have a friend who is a wiz with electonics and can take a detailed look.

[KJonno40]

Hi Ian,

Thanks very much for the advice. The alarm is going off for around 8 seconds, certainly no more. Regarding add on's I have nothing on the car that is not factory fitted. I am going to try the Battery "re-boot" you suggested and also change the remote Battery just in case. I too thought the 2 hour delay must have been significant.It is literally 2 hours to the minute/second (sad as I am I have timed it!).

Your comment re the internal Battery worries me slightly as I certainly don't have the confidence to start opening the system up. I will try the other two fixes first, see what happens.

Thanks again

Keith

Problems like this can be very difficult to diagnose at a distance.

First some basic checks.

1) Do you have any after-market accessories connected to the car electrics, Phone, IPOD or TomTom charger non standard radio etc etc?

If so remove/disconnect them all. It's feasible a charger could be triggered by say a TomTom’s internal charge circuitry to top up the battery, cause a voltage spike and trigger the alarm.

(However as explained below it would not explain the very short alarm sounding)

2) Change the batteries in all the remotes, some alarms have a panic feature which maybe ? (long shot) is being triggered by a low battery in a remote.

3) Does this happen when you leave the car at home or anywhere ?

(This is highly unlikely, but it happens at just one location it may be that an some external source, local radio ham,new cellular mast, etc may be causing a problem)

The fact the alarm is going off at regular intervals is I think is very significant. (To me it feels like a timing/charging circuit somewhere tripping in?)

Also very interesting is the fact that alarm only sounds for a few seconds (do you mean a few, as in under 10 ?)

If something was causing the alarm to trigger every two hours, I would expect it to sound for the full period ie 30 seconds at least. If the alarm is not sounding for the normal period I would tend to suspect an alarm problem.

(unless it was some form of panic alarm being triggered?)

Some ideas

You could try disconnecting the Car Battery for a minute and seeing if this resets anything.

Some Toyota alarms are fitted with internal rechargeable cells to power them if a thief disconnects the battery. I have long suspected that as these alarms get old the nicad batteries will age and to lose their ability to hold charge, even becoming low voltage (as one or more battery cells goes bad). This can lead to erratic behaviour, as used to happen in the days when "after market" alarms were fitted. I don't know of any way to check this out without taking the alarm apart and checking the internal battery with a meter.

In summary, if you draw a blank with the accessories and the alarm continues to trigger every two hours for a very short time (under ten secs) I suspect that the alarm (or possibly one of its sensors) has an internal problem. This probably means a trip to the dealer unless you have a friend who is a wiz with electonics and can take a detailed look.

[ashwaan]

Did you resolve this problem?

I have exactly the same problem. Alarm keeps going off every 2 hours exactly - although mine sounds for the full 30 seconds or so.

Rebooted by Battery disconnect - same problem.

All batteries in remotes changed too.

Email me

[kenneth Batty]

i too have same problem on rav4 i purchased last week i have fitted spacers to all door buttons and bonnet button to ensure they are closing properly,wd to all locks key in out in out etc

Battery removed trickle charge 24 hours

fob Battery renewed

 

losing my rag a bit now

 

fuse boards do not tally with drawings in hand book for rav so not sure if i have correct book

one book says fuse 31 for alarm the fuse 31 is detailed as radio

so any help advice gratefully appreciated 73 year old widower

[cruella]

I have exactly the same problem with my '55 XT4! It has only just started happening, I have done the Battery thing and will change the key fob one, but I don't think it's that as it is relatively new. It is very frustrating as I don't feel I can leave the car anywhere. I would be happy to disable the alarm altogether - is this possible?

Any advice welcome...

Cru

[Heidfirst]

the manual should tell you. Often locking the doors with the mechanical key does not set the alarm.

[IanML]

My 2005 4.2 has the TVSS IV-D system.  This manual describes how to determine what has caused the alarm to go off.  It also describes how to set the "dealer-set" options.    You may be able to use those to reset the software, if it's an "undocumented feature" (i.e. glitch).

The fitting instructions may be helpful to find the various components

[cruella]

Thank you ever so much for the replies and the manual. I had read through the owner's manual without finding anything helpful, so I will work my way through this in the hope that I can solve the problem. Until then I have been locking it with the spare key in order to stop  the neighbours blowing it up!

I will report back...

Thanks again.

 

 

[Perfection]

Could you also please check the bonnet switch fitted near the bottom side of the windscreen (cowl??). On my I see lots of rust so it could have poor contact in yours.

[IanML]

On 5/28/2017 at 10:12 AM, IanML said:

The fitting instructions may be helpful to find the various components

If you want to disable the alarm without affecting the central locking, try unplugging the TVSS ECU (pages 28 & 29).  It sounds as if you would have to drill out the blind rivets. 

With any luck, that should do it.

[FROSTYBALLS]

The one thing to bear in mind is that disabling the alarm isn't really solving the issue, and will affect your insurance - ie if the car is stolen whilst the alarm is disabled, it could invalidate any claim.

Maybe best to get an auto electrician or car alarm specialist to look at it.

[IanML]

My impression is that insurance companies are interested in the immobiliser rather than the alarm.  On this vintage of RAV4, they are separate systems.  I believe the immobiliser is factory-fitted, whereas the alarm was fitted in the country of sale (hence the instruction book).  In all likelihood, disconnecting the TVSS ECU will not affect the immobiliser.

[FROSTYBALLS]

13 minutes ago, IanML said:

My impression is that insurance companies are interested in the immobiliser rather than the alarm.  On this vintage of RAV4, they are separate systems.  I believe the immobiliser is factory-fitted, whereas the alarm was fitted in the country of sale (hence the instruction book).  In all likelihood, disconnecting the TVSS ECU will not affect the immobiliser.

Insurance companies look at the specification of the vehicle. If an alarm was part of the standard specification of a UK market vehicle, irrespective of whether it was 'factory fit' or fitted by the importer, that additional security measure would have been taken into account in deciding the insurance group for that vehicle.

Nothing to do with the immobiliser.

So disabling an alarm that was part of the vehicle's standard spec, reduces the security of that vehicle, and in the event of a claim, whether the vehicle was stolen or broken into, could affect the validity of any subsequent claim.

Disabling the alarm would also provide more time for a thief to work around the immobiliser.

As I said earlier, disabling the alarm isn't solving the issue.

[cruella]

I will get my electrically minded friend to have a look using the manual. Failing that I will take it to an alarm person. Changing the batteries didn't work, so for parking whilst at work I have been using the spare (non alarmed) key to lock up. I got the waggy finger last week as the alarm kept going off and disturbing the neighbours!

Once again, thanks for all your help!

[IanML]

2 hours ago, cruella said:

... so for parking whilst at work I have been using the spare (non alarmed) key to lock up.

I believe you can use the key with buttons as well.  Just lock by turning the key without pressing the buttons.  The special feature of the Sub key (valet key) is that it will not unlock the glove box.