Alarming Issue

[Grim Rider]

Hi, new to the forum and have an issue with my car, a 2006 Prius II T4 which has covered 38k miles. Stopped outside my brother's house last night and a few minutes after locking the car the alarm went off - now every time I lock the car it goes off after a few minutes. Have tried moving car, opening and closing all doors, turning off movement sensor. As soon as I take the key out of the ignition the red immobiliser/alarm light comes on and then flashes when the car is locked. had to leave it in his garage with the key in the ignition as the only way to stop the alarm going off! Any ideas of what to do very welcome! Thanks for reading this

[acetip]

hi,dont have a prius myself. but if you put in ALARM in the search section on top right of this prius forum,there is advice to others having simuler problms.

hope this helps.

[dwilson]

You need to get this checked!

Reminds me of many years ago when my Toyota was left with its lights on (don't know how I missed the buzzer alering me).

After a time the alarm went off. I couldn't see any reason why so switched alarm off and locked car back up.

Later when I tried to start the car it wouldn't and I had to get the AA out.

Apparently the alarm was sounding to warn me the Battery was getting flat.

Maybe your Battery needs cahnging? Just a thought but I would get it checked.

Others on here may have better thoughts!!

David

[timberwolf]

Yep, a low 12V Battery is one possibility.

There is a also a little storage compartment, for sunglasses, if you leave anything stowed there it can apparently upset the motion sensor.

[Grumpy Cabbie]

If the 12v Battery is still the original you might want to get it replaced. They're about £100 from a Toyota dealer but are a weird size so you might have a job sourcing one elsewhere.

When they start to fail the car does all sorts of weird electric gremlins.

[Peter Sale]

It sounds like you tried everything but I just wonder what will happen if you just lock the door with the metal key rather than the key fob ?.

I thought the red flashing light in the dash was just the immobiliser, not the alarm. Mind you, it fooled me when I picked up mine three weeks ago as I hadn't seen that on the test drive or when I collected it - frantic manual reading time !!

Interesting about the extra compartment - currently have my sunglasses in there.

Still sounds like the advice given is correct but please let us know - and best of luck.

Peter

[Grim Rider]

I did the Battery check this morning from the car's self diagnosis - was a little outside quoted parameters (12.1V no load, 11.7V under load, and 12.5V when charging). Drove car down to Toyota Solihull who checked and said it was fine - of course alarm has stopped going off this morning but I think it is the original Battery so shall order a new one if it does it again! Thanks for all the responses, was tearing my hair out last night :)

[Grumpy Cabbie]

My money is still on the 12v being the cause of the problems. Is it the original 12v? Do you do lots of short trips? Has the 12v ever been allowed to go flat? Have you ever jump started the car?

[twohats]

Same thing has happened to me, but only two or three times, on a similar car (2006 T4). I have had the (original) Battery checked by the dealer who say it is ok.

I have noticed that the car sometimes does not double lock on the second press of the remote but not yet proved if this is what causes the alarm to go off. When double locking works normally there is a different 'clunk' and the indicator lights do not flash on the second press.

Have you tried opening and re-closing all the doors?

I wonder if one of the door locks does not properly register that the door is closed/locked.

[Grumpy Cabbie]

Trouble with taking the car to the dealers to check the 12v is that it will have charged up by the time you get there. Apparantly it doesn't need to be too far off perfect for electrical gremlins to occur.

I would hope both Grim Rider and twohats check out the US PriusChat forum and search the many many many posts about electrical gremlins and alarm/locking issues on cars that are about 4 or 5 years old and still on their original 12v Battery. (In fact I notice Mr Grim has already posted this problem on the US forum and the concensus of opinion was a faulty 12v.)

Obviously without seeing your individual cars or testing the Battery myself I can't say its defo your 12v but there are so many reports of similar incidents that end up being the 12v that it is worth further investigation. A easy check of the 12v is to leave the car overnight and then turn the car in 'accessory' mode (NOT Ready mode) and wind all four windows down and then power them all back up together. If they struggle significantly you have a 12v issue. If they operate as if the car was in Ready mode then the 12v sounds ok.

Check out the following link;

http://priuschat.com/forums/newbie-forum/73400-weird-stuff-happening-mpgs-dropping-test-battery.html

[twohats]

I take your point about the Battery, the electric window test was pretty conclusive, and the voltage dropped below 11V in the process.

Still not sure there isn't a different problem with alarm / locking. After all it occurs at the end of a journey when the Battery would be fully charged.

I don't mean to hijack the thread. Has the OP solved their problem I wonder?

[Grumpy Cabbie]

This is the problem. A question is asked and then when a solution is found the forum is not updated

Just incase anyone else has a similar issue to the poster I would suggest you check out the following link;

http://priuschat.com/forums/gen-ii-prius-main-forum/91700-why-my-alarm-going-off.html

It appears a problematic alarm is a sign of a failing 12v. Not that I want to say I told you so.

[timberwolf]

Trying to jump start the thread Grumpy :)

Edit: Having now read the PC thread the OP has replied that their 12V Battery was replaced recently - so it looks like that thread may be worth watching to see if they get to the bottom of it. Faulty transducer anyone?

[Trafficman]

I had a similar problem with my ml ii and ended up being a component in the assembly where the internal sensors were.

Good luck, it took 4 days at the dealer, and a lot of threatening from me before it was sorted by Mr T technical asking for the part no and going "oh yes"