Alarm going off

[Rushy67]

Hi guys

My car is stored outside under a cover, it has been particularly windy with driving rain today and the alarm has gone off quite a few times.
It has been outside in similar conditions before with no problems.
I have started the car, car battery is fine. The battery in key fob appears fine, light on fob is bright.
The alarm light on the heater control is flashing at the correct blink rate.
I have locked the car manually using the key, will this leave it locked without the alarm set?
I am travelling away for work tomorrow and don't wish to upset my neighbours with the alarm going off all day.
If I disconnect the engine battery will that disable it? if so which should I disconnect the positive or negative terminal?
Any ideas?

[Carolyn]

Wet and windy can tend to be alarm-going-off weather.

I usually disconnect the negative (to avoid possibly arcing a spanner on the positive)- but whatever's easier will do.

[Chilli Girl]

You have an alarming Bambi Nick!   The only time Foxy's alarm went off was when a frog that I had transported from Somerset to Wiltshire unaware that it had taken residence inside a bag of plants I was bringing home!  That night, the little blighter had woken up and set the alarm off a few times and when I went to use the car for work in the morning, there it was sat near the handbrake waiting for a ride!

[scm2004red]

I would like to leave my car with the battery disconnected, but if i do disconnect it, the alarm beeps away to itself and the aerial pops up! Is this normal?

[Ardent]

@Rushy67

Another option to try. Give it 3 blips on the remote. This disables the interior sensors. Or better still. If going away for a while disconnect the negative as C says.

[Ardent]

I would like to leave my car with the battery disconnected, but if i do disconnect it, the alarm beeps away to itself and the aerial pops up! Is this normal?

I do find that a bit bizarre. What is powering the aerial if batt. disconnected? Residual current somewhere? But why would it go up. I take it, it's not a stock radio.

[scm2004red]

I do find that a bit bizarre. What is powering the aerial if batt. disconnected? Residual current somewhere? But why would it go up. I take it, it's not a stock radio.

it puzzles me, it is an aftermarket radio which makes me suspect the wiring to the aerial, but the alarm bit confuses me also, presumably they have some sort of back up battery.

Battery drain on this car has always been a problem, I understand that these cars do have a residual draw down of some sort if left, but mine always seems to be higher than I would consider normal. Aftermarket add ons are always favourite and the radio is the only change I am aware of.

[1979scotte]

I do find that a bit bizarre. What is powering the aerial if batt. disconnected? Residual current somewhere? But why would it go up. I take it, it's not a stock radio.

it puzzles me, it is an aftermarket radio which makes me suspect the wiring to the aerial, but the alarm bit confuses me also, presumably they have some sort of back up battery.

Battery drain on this car has always been a problem, I understand that these cars do have a residual draw down of some sort if left, but mine always seems to be higher than I would consider normal. Aftermarket add ons are always favourite and the radio is the only change I am aware of.

Battery drain isn't that bad on these.
Think about it theyre rarely daily driven and how many people use a trickle charger or battery isolator?

[Joesson]

A capacitor in the alarm would retain power with the battery disconnected, I know not whether the alarm system does feature a capacitor.

[Alex Knight]

I'm surprised no one has mentioned this, but you can verify what the latest alarm trigger is. See page 18:

https://www.toyota-tech.eu/aimuploads/%7B1B61A262-6063-4E19-80F5-01ABC951B6F6%7D/TVSS%20setting%20guide%20for%20TVSS%20IV-S%20%20LHD%20T4SLSET-2-0-F.pdf

You will then understand what is
causing your problem.

[scm2004red]

Interesting, I note that this is system TVSS-4S, my system is TVSS-4D, wonder what the difference is?

[paulj]

@Rushy67 with the wind in Devon this weekend that could be the culprit.  On the odd occasion mine is in the garage sometimes slamming the garage door will trigger it.

You can change the motion detector sensitivity, its on a small box that sits behind the centre console, towards the two rear bins.  Take out the centre plastic and perhaps the bin doors off, then its behind the carpet.  As others say, 3 blips will disable the mention detection anyway.

One other thing that we haven't covered is doorbells and Wi-Fi - as they now use the frequencies which used to be allocated to car alarms and security systems.  Some people have experience of the alarm triggering for a new wireless doorbell nearby!

You are probably on your travels by now, but locking it with the key in a door barrel will secure the car without the alarm being set.

[Rushy67]

Many thanks, did as you said and locked the door manually, so far had no reports of it upsetting the neighbours whilst I am away.

[Alex Knight]

Many thanks, did as you said and locked the door manually, so far had no reports of it upsetting the neighbours whilst I am away.

Hopefully you understand that your car alarm isn't active when you lock it with the key?

[1979scotte]

Many thanks, did as you said and locked the door manually, so far had no reports of it upsetting the neighbours whilst I am away.

Hopefully you understand that your car alarm isn't active when you lock it with the key?

I think that's why he has done it.
The immobiliser is fully active though.

[Brackers]

You can find the source of the last alarm by following the toyota procedure given below. It works on my 2003 Mk3 MR2 fitted with standard factory alarm, and probably many other toyota models from that era .

My alarm was going off intermittently, usually in wet and windy weather, even after I unlocked the car with the remote fob. The procedure found that the last alarm was caused by the interior motion sensor.

I tried lowering the windows, dropping the roof, putting the roof back up and closing the windows again. That stopped the alarm from going off even in the bad weather. I assume that a small gap existed between a window and the roof, allowing wind through and triggering the alarm.  So if it happens in future I will go through that cycle of dropping and raising the roof again.

As others have said, you can also adjust the sensitivity of the interior motion sensor. The box sits beneath the bin lid behind the drivers seat on uk RHD cars. Remove the bin door, pull the carpet back and its just there

[Brackers]

Thought I'd link to this useful alarm installation doc used by Toyota dealers at the time, to install  OEM alarms to MR2s. I tried to attach it, but at 1.4Mb, it's size breaches the post limit for this forum.

https://www.toyota-tech.eu/aimuploads/%7B2A1E08D2-D21D-4CEE-8D05-426DE1A3B964%7D/TVSS%20RHD%20T4RW3-F.pdf

[normanh]

3 Blips on my key automatically sets the alarm off every time and has always done so since I have had the car which is over 18 years now.

One locks the doors, two sets the deadlocks.

Norman

[Brackers]

I have finally fixed my troublesome MR2 Roadster alarm.It was going off 25 seconds after locking it. Following the diagnostic process, identified the cause as the interior movement sensor. I swapped it out for one from a breaker on ebay. The sensor appears to be used across several Toyota models of the period. To access the sensor, you need to remove the centre console and both storage bin doors. To remove the centre console requires you to unbolt the seats (4 x 14mm bolts), allowing access to the front console screws. No need to  take the seats out of the car. The sensor is stuck to the body using double sided tape.
You cannot view this attachment.
You cannot view this attachment.You cannot view this attachment. 

[Gaz mr-s]

I have finally fixed my troublesome MR2 Roadster alarm.It was going off 25 seconds after locking it. Following the diagnostic process, identified the cause as the interior movement sensor. I swapped it out for one from a breaker on ebay. The sensor appears to be used across several Toyota models of the period. To access the sensor, you need to remove the centre console and both storage bin doors. To remove the centre console requires you to unbolt the seats (4 x 14mm bolts), allowing access to the front console screws. No need to  take the seats out of the car. The sensor is stuck to the body using double sided tape.

I have finally fixed my troublesome MR2 Roadster alarm.It was going off 25 seconds after locking it. Following the diagnostic process, identified the cause as the interior movement sensor. I swapped it out for one from a breaker on ebay. The sensor appears to be used across several Toyota models of the period. To access the sensor, you need to remove the centre console and both storage bin doors. To remove the centre console requires you to unbolt the seats (4 x 14mm bolts), allowing access to the front console screws. No need to  take the seats out of the car. The sensor is stuck to the body using double sided tape.

I did a search & came across this.....I asked on here a few months ago & wasn't made aware of this. Same fault.  Thanks 'Brackers'

I did a search & came across this.....I asked on here a few months ago & wasn't made aware of this. Same fault.  Thanks 'Brackers'