Originally Posted by Zeta2

Really sorry to hear of your nightmare (at least mine died on the driveway, but next time it could be anywhere.)

My MY22 XC60 is still with the dealer after two weeks – most of this time being taken up trying to argue that Volvo UK should cover the replacement of the 12v battery under warranty, which they eventually did in the end of last week. But the definitive cause has still not been discovered.

From my conversations with my dealer and conversations on the Volvo forums, there still does not appear to be one definitive reason for what is causing the ‘spontaneous dead car syndrome’.

So far there have been a number of possible culprits identified:
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• TCAM damage due to roof seal leak
• Software version bugs
• False charging system and its communication between the 12v and 48v battery making the battery think it’s charged

What version software are you currently on?

Out of the three possible culprits above, I’m beginning to lean towards the false charging issue as my car died after a long 250 mile run – a bit like your long run.

Volvo must conclude this issue as the number of people suffering spontaneous dead car syndrome is growing.
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Originally Posted by JohninUK

Dealer now says that it was the TCAM communications with the TCAM batteries and battery system that caused main battery to drain. Software patch applied as per the Technical Service Bulletin. Dealer advised that our particular chassis was not included in the original recall for this issue ! Not sure I fully understand it all yet , still awaiting the full diagnostic report before taking the vehicle back Will update this thread when we get the report. Fortunately, after some hassle and poor comms with Volvo Assist we did get a replacement vehicle.