Whenever I open the bonnet on my 2012 V60, perhaps to fill water reservoir, check oil etc, and close the bonnet after, the 'bonnet open' warning appears on my dash and red warning triangle stays displayed. Then, when left overnight, of course, this triggers the alarm as the car thinks someone is opening the bonnet !. Sometimes it will take a few days and the car will realise the bonnet is closed and the warnings will disappear.

Any idea how to resolve or even where the bonnet sensor is ?

 

We use a fair amount of silicone spray around the shop.

https://www.walmart.com/ip/CRC-05074...5-Oz/116439439

I'm just showing you this because you can find it at Wal Mart by the can. We spray the inside of the latches including those on the door to clean and lubricate the assembly. Try this first.