Volvo guard alarm help please!

[thomasmann]

Volvo 940 1994 Automatic
Volvoguard Alarm 1

I’ve never used the alarm system and its siren is disconnected.
I’ve always used the driver’s door key to unlock and unlock the central locking
all the time I’ve had the car, without trouble until now.

Parked car on my drive unlocked.
Returned to car and found it locked.
On unlocking and opening the door the hazard flashers flash continuously
and the starter is immobilised.

Disconnected battery and left car overnight.
On reconnecting the battery the hazards flash and the starter is immobilised.
Any ideas, anybody, please?

[Laird Scooby]

Originally Posted by thomasmann

Volvo 940 1994 Automatic
Volvoguard Alarm 1

I’ve never used the alarm system and its siren is disconnected.
I’ve always used the driver’s door key to unlock and unlock the central locking
all the time I’ve had the car, without trouble until now.

Parked car on my drive unlocked.
Returned to car and found it locked.
On unlocking and opening the door the hazard flashers flash continuously
and the starter is immobilised.

Disconnected battery and left car overnight.
On reconnecting the battery the hazards flash and the starter is immobilised.
Any ideas, anybody, please?

Sounds like you need to use the fob to unlock/disarm it. I take it you have the fob?

[thomasmann]

No, I don't have a key fob and have never used one on this car: what next?

[capt jack]

Does the gearshift indicator still work? Check all the fuses. Something similar to this happened with my 1997 S90 earlier this year. It turned out to be a blown fuse in the immobiliser system.

What led a very smart garage techie to the answer was the fact that the auto-shift indicator lamp suddenly wasn't working. He figured out that this was on the same fused circuit as the immobiliser. The blown fuse was traced and replaced. We never worked out why the fuse blew, and in fact it took seven goes at replacing the blown fuse - every time a fuse was popped in it blew - before suddenly another new fuse went in and it all worked. I now keep a stock of fuses of the correct rating just in case, although 12,000 miles later it's all still working perfectly!

Whether it was coincedence or not, but I'd had a new mobile phone charger cable plugged into the cigar lighter at the time.

Don't know if the 940 is the same, but on my S90 the offending fuse was located in the fuse box that's accessed via a removeable panel in the driver's end of the dashboard. You can only access the panel with the driver's door open.

Fingers crossed that this sorts yours out too.

Jack

[thomasmann]

Capt Jack
that may be helpful, many thanks

[Laird Scooby]

Originally Posted by capt jack

Does the gearshift indicator still work? Check all the fuses. Something similar to this happened with my 1997 S90 earlier this year. It turned out to be a blown fuse in the immobiliser system.

What led a very smart garage techie to the answer was the fact that the auto-shift indicator lamp suddenly wasn't working. He figured out that this was on the same fused circuit as the immobiliser. The blown fuse was traced and replaced. We never worked out why the fuse blew, and in fact it took seven goes at replacing the blown fuse - every time a fuse was popped in it blew - before suddenly another new fuse went in and it all worked. I now keep a stock of fuses of the correct rating just in case, although 12,000 miles later it's all still working perfectly!

Whether it was coincedence or not, but I'd had a new mobile phone charger cable plugged into the cigar lighter at the time.

Don't know if the 940 is the same, but on my S90 the offending fuse was located in the fuse box that's accessed via a removeable panel in the driver's end of the dashboard. You can only access the panel with the driver's door open.

Fingers crossed that this sorts yours out too.

Jack

The 940 is very different Jack and only has a bulb to light up the gearshift selector, nothing to indicate electronically what position you'r in, just an extra bulb on the sidelight circuit as per instrument illumination bulbs.
Also the fusebox is behind the ashtray, as per 740 models - my 760 has the fusebox on the end of the dash like the 960 and S/V90 models

Good call checking all the fuses but i suspect he might be stuck without a fob as it's obviously gone into the armeded state. I have heard a dodge of removing the fuses for the Guard system to allow the engine to be started, whether that applies to this model or not i'm not sure.

[capt jack]

Begs the question as to how the car suddenly could both lock the doors and then arm the immobiliser all by itself.

Chance in a million that a nearby car has an identical transponder frequency maybe, and someone locking their own car inadvertently locked this one too? I wonder.

As well as checking fuses I think it'd be worth making sure that all the door locks are unlocked. I've had experience of a car battery going flat, which of course caused the central locking to stop working. The car was opened on the key, but only the drivers door unlocked. When the new battery was fitted the hazrds were flashing and the car still would not start. The drivers door was unlocked and open, but all the other doors were shut and locked. The situation was remedied by opening and closing all the doors, then operating the central locking system - basically to re-synch it. Possibly a very long shot, but worth a try I guess.

Jack

[Laird Scooby]

You've saved me a lot of typing there Jack by more or less answering your own question. Could be any or all of the above or perhaps just a momentary bad contact on the fuse (i've had a few blade fuses lately that although looking intact, had become corroded on the blade parts preventing current flow) was enough to trigger it.
Could be the same fuse is preventing it starting now and holding the alarm in an armed state.

I think there might be more to this than meets the eye so we need more input from the OP i think as to the circumstances surrounding the sudden arming of the alarm.

[stegreg]

I seem to remember that its possible to imput a manual bypass code. I forget if its via the Ignition key or the buttons on the screen sensor...its been some years since I did this but managed to get a dealer to get me the code to imput.

[Laird Scooby]

Done a bit of digging round t'interweb and found these :

http://www.volvotips.com/index.php/8...ervice-manual/

https://www.volvo-forums.com/t22938-...n-1995-940.htm

https://www.matthewsvolvosite.com/fo...pic.php?t=1965

Some stuff will be relevant, some not. It appears on the basic alarm (if i've read it correctly) the alarm can be disarmed by unlocking the drivers door with the key - perhaps the OP could try this by turning the key slightly further and longer to the unlock position or turning several times to the unlock position.

If that doesn't work, try lock/unlock/lock/unlock with the key several times, each turn hold it longer in a further position than normal, may or may not work but like i said, if i've read it correctly, there's a good chance.

Could also be that a half-hearted unlock was enough to unlock it but not enough to disarm the alarm or caused it to arm in the first place.

Just guessing as we still need more information from the OP.