Alarm triggering

Post by **fazool** » 08 Mar 2012, 11:18

Stupid Car Wash

My wife took her nice new truck to the good car wash for its daily bath.
I took the newer Volvo to the same good car wash for its end of the winter season ritual.

The older Volvo was feeling left out so I took him to the cheap automated car wash to get the road salt out of his system.

For the next two hours I was resetting the alarm and running the car to dry it out and spraying everything electrical with WD-40.

Apparently, either the siren module or one of the sensor/switches got water inside it from the chassis bath. Arg!

I've installed a few sophisticated after-market alarm systems (back in the day) and they often had an indicator what tripped the alarm (e.g. door switch, motion sensor, etc.).

If a Volvo alarm goes off, is there any code stored anywhere to indicate what exactly Which sensor or switch triggered the alarm?

Post by **regent** » 08 Mar 2012, 11:46

The DIM message will be 'Alarm Service Required' if a failed siren module causes it to trigger. Usually it is one of the UEM comm-related codes (Upper Electronic Module communications), which can be read with VIDA or other volvo capable scan-tool.

If your UEM is off-line, you would lose the sunroof controls.

I recall seeing a good write-up on the siren module here that helped me with mine. The internal battery had leaked and corroded lots of the traces and a few components on the PCB, so I just replaced it and cleared the codes. My symptoms were random alarm trips (emergency flashers ON with a very faint siren 'voice'; I wonder how it still had a voice with the condition I found the board in...)

Post by **regent** » 08 Mar 2012, 11:53

PS

This is the Siren Replacement write up: https://www.matthewsvolvosite.com/forums/vie ... en#p225926

If this is your problem, you can have the stealership do the job and then you forward the bill to that Stupid Car Wash that caused it to fail in the first place

Post by **fazool** » 08 Mar 2012, 11:59

Thanks - I saved that PDF just in case.

I drove the car today and it seems fine so far. The siren, however was very weak and there was no lights blinking or horn honking so I do think it was the module

Post by **regent** » 08 Mar 2012, 12:08

Here is an even better procedure with a supplier link:
https://www.matthewsvolvosite.com/forums ... ?t=17479&p..
If you DID see the releated DIM message above, it would be a good idea to have the new module at hand (unless you feel like repairing it).

Post by **fazool** » 13 Mar 2012, 09:06

I am looking for some thoughts on an alarm malfunction.

Background and Symptoms:
--------------------------------

The car in question is a 2001 S60 2.4T with 142K on it, meticulously maintained and in excellent condition.

Last weekend, I ran through a car wash and after getting home, I parked and turned off the car. A few minutes later, the alarm siren triggered and was sounding off. I had to reset it with my remote. This happened about three times. When it was alarming, the siren was really muffled and quiet sounding. I ran the car on the driveway for a little bit to "dry it out" and the problem went away.

Last night it was raining out and I went for a drive. This morning when getting in the car, I noticed the LED was flashing rapidly until I started the car (indicating the alarm had triggered during the night).

This morning, we still had water on the roads and a light rain during my morning commute. I got to work, parked, turned off the car and went inside. A few minutes later (maybe two?) the same thing happened with the siren sounding off. The siren volume was very strong this time.

The message center simply said "Alarm Triggered Check Vehicle". I turned it off with the remote and left it unlocked so it won't re-arm.

I've scoured the various forums and web posts and the only common thread I can find is that the siren module might be faulty, with a particular suspicion of the old internal rechargable battery.

Questions and Ideas:
--------------------------------

If the rechargeable backup battery is getting old, shouldn't that throw a fault with an "alarm Service Required" message?

It may be coincidental but I suspect water is playing some part in this malfunction.

Is there any way to determing which sensor triggered the alarm (was it a hood switch or door etc) ?

I know the siren module is sealed. Has anyone identified the replacement rechargeable battery for this?

Is there a way I can decipher if my car has the optional motion and tilt sensors?

I suspect the rechargeable internal siren modul battery (especially since it was sounding so weak before) but I can't figure out why the water is making it worse. Any ideas?

All the door latches and hood latches and switches work fine.

Post by **fazool** » 13 Mar 2012, 13:49

Warm sunny day here since I got to work.

Car has dried off and not a peep from the alarm.

I definitely suspect water shorting something.

Now to find out what and where.

And to see if somehow there is some link to the water appearing on my driver's floor (no coolant - just water)

Post by **regent** » 13 Mar 2012, 15:36

Suggested answers to your Questions and Ideas:
--------------------------------

If the rechargeable backup battery is getting old, shouldn't that throw a fault with an "alarm Service Required" message?
Yes, there is usually a DIM message.

It may be coincidental but I suspect water is playing some part in this malfunction.
It is likely the connector to the Siren that is getting the water.

Is there any way to determing which sensor triggered the alarm (was it a hood switch or door etc) ?
Yes, by talking to the car with VIDA

I know the siren module is sealed. Has anyone identified the replacement rechargeable battery for this?
Yes, you may have seen links in the posts that you combed through. I recall it was a 7.2V

Is there a way I can decipher if my car has the optional motion and tilt sensors?
VIDA will give you a printout with the config specifics, or you can speak with the stealership, they can interrogate the DB by VIN.

I suspect the rechargeable internal siren modul battery (especially since it was sounding so weak before) but I can't figure out why the water is making it worse. Any ideas?
I am not sure if you will like this answer but "Water and electricity do not mix very well together"

All the door latches and hood latches and switches work fine.
The System performs a self test when armed and if it fails it will display a message and store (a) code(s).
If it arms properly, then all inputs function as intended.

(Just suggestions)

Post by **fazool** » 13 Mar 2012, 15:56

Thanks. No DIM message and all inputs semm to be working so it sounds like I'm down to siren module shorting or internal battery.

Post by **regent** » 13 Mar 2012, 16:15

I would as well suggest inspecting the siren's electrical connector but getting to it just to do that would not be justifiable unless you are ready to fix the sick module (or you have a replacement on hand).