Thread: L322 TD-6 Alarm going off

Hi Utemsn, I’ll be very interested to see where this thread ends up. Mind is a 2003 V8 so I don’t think this issue is related to engine stuff. I replaced the centre roof sensors with one from another vehicle and the problem went away however the alarm went off at around 1 am this morning very similar symptoms to your self, I have also fond the double press on the key fob which is meant to disable the motion sensor bit, this didn’t work so I am now starting to look elsewhere not sure where to start. Interesting.......

Cheers Marty

Originally Posted by Nomad9

Hi Utemsn, I’ll be very interested to see where this thread ends up. Mind is a 2003 V8 so I don’t think this issue is related to engine stuff. I replaced the centre roof sensors with one from another vehicle and the problem went away however the alarm went off at around 1 am this morning very similar symptoms to your self, I have also fond the double press on the key fob which is meant to disable the motion sensor bit, this didn’t work so I am now starting to look elsewhere not sure where to start. Interesting.......

Cheers Marty

Nomad 9: At one time I thought it was the seat pad sensor in passenger seat as it was not working correctly resulting in the airbag light staying on longer than it should so I reckoned it was changing resistance after I locked the car thus making the electonics think someone sat onto or got off the seat cushion..
I bypassed the seat-pad with a little electronic piece that you can buy online for many BMW's which of course is where the seat and electronics came from.
As you have tried replacing the volumetric sensor I might give the tilt sensor (under passenger seat) a go and see if that makes any difference.
I will get right onto that and report soonest.
Happy New Year to any readers.
Ray

The bonnet switch is a common fault point for L322 alarms. Mine used to go off randomly, unplugged the bonnet switch and it has been good ever since.

Originally Posted by BigJon

The bonnet switch is a common fault point for L322 alarms. Mine used to go off randomly, unplugged the bonnet switch and it has been good ever since.

I had this problem at one stage and the problem was the bracket holding the bonnet switch. The bracket was cracked which let the switch drop a little. The switch would think the bonnet was open and sound the alarm.

Like Jon, I unplugged the switch until I got around to fixing the bracket.

Hi Uteman,
Very interesting you mentioned the pressure sensor in the passengers seat, new years eve was the first time my wife had been in the vehicle for quite a while, I might have to look into this a bit further. I'll also check the bonnet switch, I have also had the bonnet open a lot lately doing "other stuff", this could also be a culprit.

Cheers Marty

I had a alarm go off when the voltage dropped during the night maybe check your resting battery.

Hi Roverlord,
I am keenly awaiting the arrival of my battery monitor hardware that has a phone App attached to it. I've already fitted one to my RRS and it is working a treat, don't want to take the unit off my RRS because I am monitoring that one at present quite closely.

Cheers Marty

I've had instances of alarms twice over the 9 years of ownership.

once we had the alarm going off nightly, and I assume during the day also. Until the biggest huntsman spider I've ever seen was spotted climbing out from the base of the windscreen. No more issues after the car was dutifully bombed....

UNTIL: couple years later, car in garage, not locked , alarm going at 1am. Key button wouldn't turn it off, when I open the door (to pop bonnet) I notice no interior lights but didn't put it together. Disconnect battery - alarm continues. By this time I have neighbours from both sides, in pyjamas, looking at it puzzled (like me!). After a bit of umm/arh the lack of interior lights was recognised - a battery charger was connected which was enough to power the car up and the key would then work. Collapsed main battery, I assume alarm had triggered with the sudden voltage change even though the car wasn't locked - and it's obvious the alarm has a good capacitor to keep going for quite a while after the battery exited the equation.

This then raised the question "what would we do if the car was locked?" - which led to some research on that. For obvious reasons I won't publish the answer on a public board....