2005 D5 Alarm Service Message

[aslan]

I don't leave anything electrical, ipads and such in the car. Main battery is a few years old with the connections clean.

The alarm triggering almost always oddly occur at work. The sirens would come on with the lights blinking, and I'll get a call from security or my colleagues informing me that my Volvo is going bonkers. And it occurs a few hours after parking the car at work. We have designated parking lots and my car neighbors are the same. No accidents.

So far the alarm only once have been triggered at home

[aslan]

Originally Posted by SwissXC90

Check also for broken windows, lock interference, and if the car has been bumped into (ie: not a false alarm!)

What do you mean by checking for lock interference?

[gmonag]

The cause of an alarm trigger can be read out from VIDA. They are stored in the REM.

[Simon Jones]

A common cause of false alarms is large diesel vehicles going past yours. When I lived in a narrow terraced road, the ADSA home delivery truck inching its way slowly past the parked cars would often set it off.

[aslan]

Originally Posted by gmonag

The cause of an alarm trigger can be read out from VIDA. They are stored in the REM.

Many thanks! I've been searching for that function even before I removed my siren.

Excluding me testing the siren, which works, two of the alarm triggers were due to 'mass movement sensor, rear'.

At first there was no fault code pertaining to this sensor. In the course of exploring the functions in REM and UEM, I configured the siren module. And after that, DTC UEM 000A movement sensor communication fault, appeared.

I guess I should try cleaning this sensor connection first? Anyone else have had this fault?

[SwissXC90]

Originally Posted by aslan

Many thanks! I've been searching for that function even before I removed my siren.

Excluding me testing the siren, which works, two of the alarm triggers were due to 'mass movement sensor, rear'.

At first there was no fault code pertaining to this sensor. In the course of exploring the functions in REM and UEM, I configured the siren module. And after that, DTC UEM 000A movement sensor communication fault, appeared.

I guess I should try cleaning this sensor connection first? Anyone else have had this fault?

Do you actually have both movement sensors installed?
There is a front sensor (around the rear view mirror) and a rear sensor.
It is possible your car only has the front and not the rear mass movement sensor fitted.

If both fitted, then of course nothing will happen as long as the rear sensor is not communicating.
It is on a LIN bus so easy to diagnose, use the wiring diagram and check the bus connection and power to the sensor is all ok

[gmonag]

DTC UEM-000A should not trigger the alarm. On the contrary, it should just prevent the mass movement sensor from triggering an alarm.

The sensor may be faulty and producing false alarms. That may also set the DTC. If you have an oscilloscope you could probe the signal.

[aslan]

Originally Posted by SwissXC90

Do you actually have both movement sensors installed?
There is a front sensor (around the rear view mirror) and a rear sensor.
It is possible your car only has the front and not the rear mass movement sensor fitted.

I'm not sure. Have to do some searching for this on the XC. I do not recall any sensor upfront when the headliner was removed.

[aslan]

Originally Posted by gmonag

DTC UEM-000A should not trigger the alarm. On the contrary, it should just prevent the mass movement sensor from triggering an alarm.

The sensor may be faulty and producing false alarms. That may also set the DTC. If you have an oscilloscope you could probe the signal.

You're right.

After a few days, the alarm have been behaving. But for the past few days I've been working at another site, so will have to see if it's activated again when I park in my usual parking bay at work.

I connected my VIDA and erased both the DTC for the mass sensor and the siren. While playing around and trying to test the mass movement sensor I came this function



I activated the voltage supply to the MMS and nothing happened. What is the purpose of that function and how does one utilize it?

[cheshired5]

Originally Posted by aslan

I activated the voltage supply to the MMS and nothing happened. What is the purpose of that function and how does one utilize it?

Is details/description highlighted bottom left when you single click on the function in the list?
If so click on details and read what it says.