Hi Alfredo,
I have a 2008 Acenta CC & had a lot of trouble with hazard lights coming on randomly and not turning off. (Other drivers were so polite and helpful in advising me of the problem!!) I had a diagnostic check done - nothing found. I therefore dismantled the dashboard to get to the BCM & sent that away to be checked but that was fine. After a few months, during which I disconnected the battery & kept it in the garage, suddenly it righted itself & was good again for a few months. Then it happened again!!!!
I went on line & this time I found someone who'd had the same problem & it turned out the cause was water ingress into the siren which is sited in the boot to the right of the spare wheel. (You might notice if you wash the car or if it rains and you lift the boot lid water will drip off it onto the edge of the boot and then runs down). The siren & hazards operate together if anyone tries to break in BUT the siren is wired separately so can be removed and the hazards reconnected. It's worked perfectly ever since. I don't have a siren any more but I do have a great little convertible with less than 55,000 on the clock that will now pass its MOT.
I can't find the original posting to say thank you but hopefully this will help someone else.
Cheers to whoever posted the one I first found.
