I’m currently away from home, with no ability to view the workshop manual and wiring diagrams.
The first indication that something was wrong with the car was when it wouldn’t lock. On checking the dash, it said the bonnet was open. When I turned on the ignition, I got several faults, including Cruise not available, Forward Alert not available, Park Brake Fault, IEB not available, low coolant. Quite worrying.
When I scanned the car for codes (because we all keep a code reader in the car, right?), there were no comms with the Speed Control Module, and many other modules had faults related to not being able to communicate with the speed control module.
I found a post on here saying that on the L322 the speed control module is at the front, near the headlight. Hey, that’s also where the coolant level sensor and the bonnet catch are!
So I am hoping that there’s a faulty earth in that area, or something like that. Might they even all lead back to the infamous wheel arch earth?
What do you all think I’m going to find when I start looking? Or does anyone know what links those three sensors?

If the battery is good, check the earths under both front wheel arches. Lots of threads on here where it all looks good but on checking they shear off. 2018 SE SDV8 4.4 Byron Blue

All grounded at the common point under front drivers side wheel arch, even if the earth looks good, put a spanner on it and check, chances are it'll snap off. L405 SV Autobiography LWB SDV8, finished in Aston Martin China Grey by ETO division.

Thanks for your help!

Now I am back in civilisation and able to access the workshop, I found this in the wiring diagram, as described:



So, as mentioned, all grounded to the same point.

Car is booked in at the garage now, as I don't want to do this job myself.

If you want to do a temp fix you can ground the earth's at the bolt for the front accelerometer which is about 10cm from the original earth, 30 mins start to end. Obviously a new earth stud or rivnut needs to be done at some point. L405 SV Autobiography LWB SDV8, finished in Aston Martin China Grey by ETO division.