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

Don't think OBD-II covers alarms.

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.

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].

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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.

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 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!

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.

The Alarm Siren is going bad it needs to be replaced

The Alarm Siren is going bad it needs to be replaced

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.

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