Strange Alarm Service required message

[mattyfezf]

Hi all, my 2001 v70 got an "Alarm Service required" message on the dash today (it could have been there a little while, but I noticed it today. it disappeared after 30secs or so, but reappeared the next time the car was started, this happened 3 or 4 times.

SO, my first instinct was to check here and I found some threads about corrosion in the siren unit, and it would need a new unit... wasn't looking forward to that!

Now the strange thing is i plugged my generic fault reader in, a U380 OBDII reader/eraser. Nothing showed up at all?

And get this, when re testing, there is now no sign of the dashboard error message?

Now one thing i didn't mention above is that one of the threads i read said they had a bit of plastic or some other debris fouling one of the door mechanisms, which was causing the error, so before attempting to read the OBDII codes, I gave all the door/tailgate and mechanisms a look over, and a good firm open and close to make sure locks and everything were engaging properly. My untrained eye noticed nothing out of place, but i cant rule that out as a factor.

There are one or two mitigating factors which may be related:

1. For the last couple of weeks I've been getting a low battery voltage warning on the dashboard - this came as no surprise as I've been doing a lot of short runs in the cold recently, with the aircon on, heated seats and radio blaring etc. This was easily cleared by giving the car a decent run and giving the alternator chance to top the battery back up.

2. Recently my alarm fob seems less responsive than usual - may be its battery is low? I should probably replace it - is it just a case of putting a new battery into the fob, or is it more complicated than that?

Any opinions appreciated... it just seems strange that the "Alarm Service required" dashboard message would just suddenly disappear!

Mind you it may be a fluke it disappearing, as I only tested it once after it didn't reappear.

Thanks

[Jim314]

Originally Posted by mattyfezf

Hi all, my 2001 v70 got an "Alarm Service required" message on the dash today (it could have been there a little while, but I noticed it today. it disappeared after 30secs or so, but reappeared the next time the car was started, this happened 3 or 4 times.

If the small battery in the siren unit is going bad, then reports are that this will drain the main vehicle battery even when the ignition is off. That would account for your low main battery.

The siren unit in my 2004 v70 failed a couple of years ago, and since then I have gotten the alarm service message when I first start the vehicle. As soon as I realized this was the case I pulled fuse #38 ('alarm') in the fuse block at the end of the dash (left side on my LHD, so presumably right side on your RHD)under the belief that removal of this fuse prevents the siren battery from draining the main battery. I had no low battery problems with the fuse pulled.

I had the vehicle into the dealer shop for service and wanted them to look at the siren and so I reinserted fuse #38, but they didn't have time or inclination to deal with the alarm. I left fuse 38 in place and later when I didn't drive the vehicle for a day or two the battery was so far down that it wouldn't operate the starter.

I charged the battery (in place in the vehicle) and removed fuse 38 and I have not had a recurrence of the low battery condition even when I haven't driven the car for a day or two.

When I lock the vehicle with the remote the red LED on the dash flashes as if the alarm were active. I am still on the original main battery after 7 years of service and 50,000 miles.

[Rossi-fan]

Common fault, you may very well need a new alarm siren

[deano70]

The alarm on my XC70 goes off once per day generally around 12pm. The display says it requires an alarm service, however, my local Volvo Specialist hasn't been able to find anything wrong. Any thoughts?

[chiptivo]

Originally Posted by deano70

The alarm on my XC70 goes off once per day generally around 12pm. The display says it requires an alarm service, however, my local Volvo Specialist hasn't been able to find anything wrong. Any thoughts?

Yes, Have a look at http://www.volvoforums.org.uk/showpo...48&postcount=2

[deano70]

Thanks, I'll give it a go and see what happens