Only one alarm fob

Alpine · Jan 10th, 2022, 19:59

So when I got my car it came with 3 keys but only one remote fob.

But its occurred to me, that if I locked my car with the fob (so setting the alarm) but then I lost the fob (or it broke), how would I unset the alarm?

I could obviously get into the key with one of my spare keys, but would not having a spare fob to unlock the car mean that the car is disabled?

CosmicBike · Jan 10th, 2022, 21:23

The alarm and immobiliser are 2 distinctly different systems, linked only through the ECU. The alarm fob communicates with the central locking and alarm module only, locking/unlocking doors and setting the alarm.
The immobiliser is switched off by the chip in the key, picked up by a sensor ring around the ignition barrel which then communicates with a separate immobiliser module.

If you lock with the remote and unlock with the key, I believe the alarm will go off, but will cease doing so when you start the car. Subsequent locking/unlocking with the key will present no further problems since the alarm will not have been set.

Alpine · Jan 11th, 2022, 07:20

Quote:

Originally Posted by CosmicBike

The alarm and immobiliser are 2 distinctly different systems, linked only through the ECU. The alarm fob communicates with the central locking and alarm module only, locking/unlocking doors and setting the alarm.
The immobiliser is switched off by the chip in the key, picked up by a sensor ring around the ignition barrel which then communicates with a separate immobiliser module.

If you lock with the remote and unlock with the key, I believe the alarm will go off, but will cease doing so when you start the car. Subsequent locking/unlocking with the key will present no further problems since the alarm will not have been set.

cheers Cosmic

SteveSarre · Jan 11th, 2022, 08:54

Hi

Yes as above. If alarm goes off, you can turn it off by inserting the key into the ignition (and possibly turning it or starting the car - I don't remember exactly which).

You can test by opening the drivers window, exit the car, set the alarm, then reach in through the window (which should trigger the alarm). Insert key etc

HTH
Steve

volvo again · Jan 11th, 2022, 09:39

This didn’t work on my 98 v70
Turned over but no start

4x4 · Jan 11th, 2022, 11:02

There is a procedure for starting when the remote stops working...

Taken from page 2:30 from the 1997 owners manual

Note the last paragraph re if the alarm has triggered...

Jan 10th, 2022, 19:59	#1
Alpine Senior Member Last Online: Yesterday 22:04 Join Date: Jan 2012 Location: Leeds	Only one alarm fob So when I got my car it came with 3 keys but only one remote fob. But its occurred to me, that if I locked my car with the fob (so setting the alarm) but then I lost the fob (or it broke), how would I unset the alarm? I could obviously get into the key with one of my spare keys, but would not having a spare fob to unlock the car mean that the car is disabled? __________________ Phil '98 V70 2.5T (manual '99MY)

Jan 11th, 2022, 08:54	#4
SteveSarre Premier Member Last Online: Yesterday 07:11 Join Date: Oct 2004 Location: London/West Country	Hi Yes as above. If alarm goes off, you can turn it off by inserting the key into the ignition (and possibly turning it or starting the car - I don't remember exactly which). You can test by opening the drivers window, exit the car, set the alarm, then reach in through the window (which should trigger the alarm). Insert key etc HTH Steve __________________ V70 2.5 Turbo AWD Man. 1999 Red V70 2.5 10V Auto 1998 Green C70 T 20V Auto Conv. 2001 Blue, C70 T5 Auto Conv. 2000 Blue V70 2.5 Turbo AWD Auto 1998 Green, V70 2.5 10V Auto BiFuel 1999 Red (scrapped) V70 20v Auto 1999 Green (scrapped)

Jan 11th, 2022, 09:39	#5
volvo again Master Member Last Online: May 7th, 2024 18:27 Join Date: Jun 2018 Location: Presteigne, mid Wales	This didn’t work on my 98 v70 Turned over but no start __________________ 1998 V70 2.5 Auto & Supercharged Mercedes C Class...

Jan 10th, 2022, 21:23	#2
CosmicBike Senior Member Last Online: May 5th, 2024 16:31 Join Date: Dec 2019 Location: Surrey	The alarm and immobiliser are 2 distinctly different systems, linked only through the ECU. The alarm fob communicates with the central locking and alarm module only, locking/unlocking doors and setting the alarm. The immobiliser is switched off by the chip in the key, picked up by a sensor ring around the ignition barrel which then communicates with a separate immobiliser module. If you lock with the remote and unlock with the key, I believe the alarm will go off, but will cease doing so when you start the car. Subsequent locking/unlocking with the key will present no further problems since the alarm will not have been set.

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