I have not checked to be sure, but suspect the pin carrying +12v is on the corner of the field.
The metal shell is, of course B-. The slightest misalignment at the critical instant will have the
case grounded, and that pin in contact thus an "STS" moment (Something touched Something)
The tiny spark is just a courtesy to let you know you need a new fuse!

Cleared fault, using Nanocom as instructed all good......but, arrived late last night and for the first time towards the end of the journey, the rear dropped to approx access height! Really strange , not had the rear, (or front on its own) playing about.

Deleted unknown fault code, switched on pump manually and Bob's a good'un!

Still haven't fitted a new set of sensors that I have for the rear. Tied up in a shed load of work on an old Boxster!

Why should the rear suddenly drop on a journey?