Car alarm problem (slightly OT to uk.d-i-y)

[Roger Mills]

The alarm on my 2007 Volvo V70 (S80 platform - not latest shape) keeps going off for no apparent reason. I can stop it happening by pressing the button to disable the spacial detector before locking the car, but that reduces the security level, so I'd rather not have to do that.

Has anyone got any experience of this sort of thing, and any bright ideas of what to look for? I've come across this sort of thing in the past when windows have been left slightly open on hot days, but all my windows and doors are firmly shut!

I guess that an OBD-II reader might throw up some codes which would offer a clue - I'll post separately on that!

[Dave Plowman (News)]

Don't think OBD-II covers alarms.

[Adrian]

If it's not something blindingly daft like a wasp or fly caught in the car, then it might be an ultrasonic sensor going south.

Unlikely. OBD just does the basics of engine management. A Volvo-specific diagnostic may well, though.

[Flop]

Had this with a 2004 V70.

What seemed to work - but eventually didn't - was taking change out of the well pocket between the seats. There was a comment somewhere referring to a sensor located there which became upset at having metal nearby.

But it may be worth a punt.

There is a known problem with the alarms of Volvos. The battery dies. [It has to be battery powered for security].

To add to your woes - replacement units are expensive [~£150*] and they are not easy to replace [obviously you would prefer if if a thief could not just unscrew it].

• -

Flop

[Roger Mills]

I'm not aware of any live creature moving about in the car, but I'll re-check. It's been doing it for far longer than the life expectancy of your average fly. Maybe spiders live a bit longer?

You may be right. My Haynes manual suggests that a Volvo dealer would be able to use some sort of diagnostic device - but doesn't explicitly mention OBD-II in this regard.

[alan]

If you haven't got a reader, a OBD-II adapter/bluetooth transmitter (ELM327) from Ebay for less than £10 coupled with the Torque App (Android and Apple) for a smart phone works very well.

I suspect that an alarm sensor may not show up on a OBD-II fault report.

[Stewart]

I had a similar problem with an S60 and found that there was a touch of dampness in a sensor at the lower part of the engine, once the dealer replaced that all was well. Also had a problem with a Volvo v50 where the problem was with the wiring to the caravan.

The alarm on my 2007 Volvo V70 (S80 platform - not latest shape) keeps going off for no apparent reason. I can stop it happening by pressing the button to disable the spacial detector before locking the car, but that reduces the security level, so I'd rather not have to do that.

Has anyone got any experience of this sort of thing, and any bright ideas of what to look for? I've come across this sort of thing in the past when windows have been left slightly open on hot days, but all my windows and doors are firmly shut!

I guess that an OBD-II reader might throw up some codes which would offer a clue - I'll post separately on that!

[Lobster]

Roger Mills grunted in news:b9lfm2F86s1U1 @mid.individual.net:

My 2003 Zafira has the same problem. I was advised that it was due to the rechargeable battery within the sealed sounder unit not having enough charge in it - the unit interprets this as someone tampering and trying to disconnect the alarm, so it goes ape-shit as a result. I had the sounder replaced (not possible to simply change the batteries) - it was a very expensive component and quite awkward to do as it's concealed somewhere up in the wheel arch - and that sorted the problem for quite a few months, however it came back.

I suspect therefore the unit's not getting enough juice off the car or something; however I've not investigated further and these days, I'm afraid I just disable it on the basis that's a pretty unattractive vehicle for tea-leaves, and there's never anything of value left inside... touch wood.

[Glenn K]

The Alarm Siren is going bad it needs to be replaced

[Glenn K]

The Alarm Siren is going bad it needs to be replaced

[Pieter]

Just seen on TV that a rat was living in a car. Lots of trouble that comes with it. Lights fall out, Alarm goes off. Idea??

Pieter

"Roger Mills" schreef > >

I'm not aware of any live creature moving about in the car, but I'll re-check. It's been doing it for far longer than the life expectancy of your average fly. Maybe spiders live a bit longer?

You may be right. My Haynes manual suggests that a Volvo dealer would be able to use some sort of diagnostic device - but doesn't explicitly mention OBD-II in this regard.

[Roger Mills]

I think if there were a rat in the car, I'd have seen some evidence by now!

[446723]

I have a Oct 2013 V70 and the alarm goes off with no good cause every 5-10 days. The interior sensor has been replaced and it then it went off the very next day. Volvo dont seem to know what to do.

[Adrian]

Does the alarm have a way of overriding the internal volumetric ultrasonic sensors when armed? If so, see if that prevents the problem. It'll isolate it to whether it's the ultrasonics or something else.

Other than that, it's a warranty problem. Keep leaning on them. If they continue to be useless, try another dealer or escalate it to Volvo UK.

Bear in mind, though, that if it IS the ultrasonics, it MIGHT be something as simple as a spider in the car...

[Davey]

...or something bigger that hides when you are in it..... with four feet....do you leave crumbs around the floor or seats?

[bert]

May be as simple as alarming it with the driver's door open.

Or leaving it with a window slightly open.

[brian.kirkegaard.horne]

Hello I have the same problem a year ago. I fix the wires to the lid in the back, as it was broken. But now the alarm has gone off several times again. Alwa ys with phones and/or Ipad in the car. So I suspect Bluetooth, wifi or mobi le-connection to be the problem. There is no messages about why the alarm has gone off. With the wires I thi nk there was a specific message. The dealership said last time I asked, that they did not now off any proble m. But it Is a problem to test, because off the Sound/noise... So I look forward to find out. I must find a place, where it doesn't matter with the noise. I have a volvo v70 II, MY 2007. I now this is an old tread, but have someone found the error. / Brian

[brian.kirkegaard.horne]

Hello I have the same problem a year ago. I fix the wires to the lid in the back, as it was broken. But now the alarm has gone off several times again. Alwa ys with phones and/or Ipad in the car. So I suspect Bluetooth, wifi or mobi le-connection to be the problem. There is no messages about why the alarm has gone off. With the wires I thi nk there was a specific message. The dealership said last time I asked, that they did not now off any proble m. But it Is a problem to test, because off the Sound/noise... So I look forward to find out. I must find a place, where it doesn't matter with the noise. I have a volvo v70 II, MY 2007. I now this is an old tread, but have someone found the error. / Brian

[brian.kirkegaard.horne]

Hello I have the same problem a year ago. I fix the wires to the lid in the back, as it was broken. But now the alarm has gone off several times again. Alwa ys with phones and/or Ipad in the car. So I suspect Bluetooth, wifi or mobi le-connection to be the problem. There is no messages about why the alarm has gone off. With the wires I thi nk there was a specific message. The dealership said last time I asked, that they did not now off any proble m. But it Is a problem to test, because off the Sound/noise... So I look forward to find out. I must find a place, where it doesn't matter with the noise. I have a volvo v70 II, MY 2007. I now this is an old tread, but have someone found the error. / Brian

[Brian Gaff]

I found this on a house alarm once and basically mobile phones and lightening tended to set it off. Small value capacitors on all the wired inputs to the alarm more or less cured it, but it still did have spurious alarms which could not be traced to anything. It might be worth a try in a car, as its bound to pick up signals on unscreened wiring, and if that is seen as somebody tampering then the alarm sounds. I believe the house alarm used something called a window comparator, so an open or short circuit set it off or in fact any liquid that partly shorted the wires. It was supposed to be anti tamper as it used a balance system to match the stable resistors in the sensors with one inside the alarm, if it went out of balance it set the aarm off. Don't know if car alarms work the same way. Brian