The alarm on my s40 is going off intermittently. One time the key fob auto lock wouldnt work at all. The lights continued to flash after the siren stopped and i had to drive it around the block to get it to stop/re-set. It has happened three times tonight. The other two times I could use the key fob. What is causing this?
Faulty Alarm on 2000 Volvo S40
You are going to need to check to see if there any trouble codes stored in the alarm module. I have seen the sirens fail on other Volvo's but not this model. This could also be a problem with the central locking system, but it's very hard to know without performing a proper diagnosis of the vehicle. (even then it can be very difficult to diagnose electrical issues)