Alarm Fault Indicator

I have an indicated fault on the alarm/immobiliser system on my 1997 V70R. The dash-top LED flashes for several seconds when I turn on the ignition, indicating a fault somewhere in the system, but I have no idea where to start looking for any apparent fault.
The alarm seems to work OK when tested, everything seems to lock correctly, and the LED flashes normally under ‘armed’ conditions.
Can anybody help me before I have to submit to Dealer Rates for an investigation, please?
(As a matter of interest, just whereabouts is the alarm siren, anyway?)

Thanks for any info,
Steve.

[liuleichan]

>I have an indicated fault on the alarm/immobiliser system on
>my 1997 V70R. The dash-top LED flashes for several seconds
>when I turn on the ignition, indicating a fault somewhere in
>the system, but I have no idea where to start looking for any
>apparent fault.
>The alarm seems to work OK when tested, everything seems to
>lock correctly, and the LED flashes normally under ‘armed’
>conditions.
>Can anybody help me before I have to submit to Dealer Rates
>for an investigation, please?

Does this necessarily mean there's a fault, though - per se?

Doesn't the light flashing, merely mean the alarm has been triggered?

Could there be something causing the ultrasonics to trigger?

Or have you done more diagnosis in interpreting the flashes?

I know the odd time mine must have gone off (saw the light flash when I turned the ignition on) on my S70, but it's only happened on truly an odd occasion (can't remember the last time).

As it happened so rarely, I always just assumed there was something (like high winds) occasionally triggering the ultrasonics (I don't tend to close the vents).

>(As a matter of interest, just whereabouts is the alarm
>siren, anyway?)

Dunno. I wouldn't mind knowing, too.

Lei Chan

I found that when I purchased the C70 ('98 model), during the period I had to rely on the Volvo alarm until my own system went in I was plagued with false alarms. Volvo checked it out and said it had been the microwave sensor (the volumetric sensor instead of ultrasonics). After quizzing their technician, I was told that the sensor for this was buried somewhere under the stereo. This is hardly a good location for such a sensor, but unfortunately they are factory set and non-adjustable. Whether this is true or not wasn't really of any concern as the OE alarm isn't being used any more, and my new system uses a digitally controlled dual zone microwave sensor located in a much more sensible place, smack bang in the centre of the car and away from metal objects.

As for the OE siren, if like the C70 it will be inside the front offside wing and makes a high pitched two-tone sound.

Max



The Leeds Clifford dealer and
North of England rep for the V.S.I.B

C70 T5 GT
480 ES
340 GL (now long gone)

Thanks for the info.
The problem seems to have stopped now - of its own accord!
(According to the owner's manual, the flashing of the dash-top LED when turning the ignition on, is an indication of a fault in the alarm/immobiliser system.)
Everything still seemed to work OK - even though it was indicating a fault. I'm intrigued to know what caused the problem, even though it seems to have cured itself.

Thanks anyway,
Steve.