On my 2006 V70 I have an issue where the driver side rear lock won't lock when the central locking button on the driver's side door is depressed OR when I use the key fob lock button. Once this happens, the central locking from the CLB functionality is disabled.
This is intermittent - usually every 5 or 6 times I lock/unlock. I can get it to start working again with a combination of manually locking and unlocking but it's a pain and makes me long for a car with manual locks (and ones where the rear door lock was positioned at the front of the door for each reaching

My reading suggests that this is either due to 1) some issue with the wiring harness as it enters the door or 2) the thermal fuse in the door lock actuator. I was going to explore both of these this weekend, but would like to understand if I need to disconnect the battery and if so, what the proper procedure is to avoid the dreaded SRS messaging that can only be reset by the dealership (or someone with VIDA/DICE).
Also, feel free to tell me if I'm barking up the wrong tree on this one.