[giantho]

Check the multi pin connectors to the CEM and in the driver's footwell behind the carpet against the kick panel. Break and if necessary clean the terminals with an electrical contact cleaner. I'm not saying that's definitely your problem, but it's a known cause of multiple unrelated fault warnings and errors. There are several related threads on here, including a recent one that included a photo of the connector in the footwell.

Thanks.
Are you referring to the assembly shown in this video?

 

[giantho]

Many thanks for your help; will give it a try one of these days.

 

[giantho]

Coming back on this. Turns out that my issue was due to my battery dying. No "Low Battery" warning appeared, but had it measured and it was almost dead. After replacing it with a new AGM battery, the issue has not appeared for the past 2 months.

 

[giantho]

@larskupen in my case the problem almost vanished after getting a new battery. It has appeared only twice in the last year. I went to an independent Volvo garage that told me it is known issue with the wiring connections; they pretty much wanted to keep the car for 2 weeks, strip off all the carpet and re-solder everything...not gonna happen. It's a pity that Volvo has not made a recall for this issue. You can probably follow the recommendations from other forum members and try to clean the connectors on the footwell and also tighten the 2 ground connectors (I believe one is in the hood by the battery and the other is behind the carpet in the driver's side - someone pls correct me if I am wrong).
Good luck!