Volvo Forums - Volvo Enthusiasts Forum - 2001 S80 siren module / interior motion sensor

Hello All,

I have a 2001 Volvo S80 T6 (two previous owners and bought last year) and I had an issue with the siren, it started and never stopped. I checked the forums and it looks like the siren module is something that usually needs to be replaced. I went to several garages and all said that I had to replace the module and estimated over $500 (labor and parts).

Then I saw the button that turn off the interior motion sensors (I didn’t realize it was there before). I switched it on and after locking the car, the problem with the siren had gone. Now, if the interior motion sensors are turned off, the siren does not sound. If I don’t turn off the interior motion sensors, the siren starts and never stops.

Does somebody know if the problem can be cause by the interior motion sensors and not by the siren module? None of the garages mentioned the sensor button. Does somebody have a similar situation or faulty interior motion sensors?

Thank you very much for your help!