What's this dodgy wire for? (not a Subaru)

[swamp]

Not sure if right subforum, defs wrong forum but i don't want to join a Nissan forum just yet.

 

Car in question is a Nissan Serena c23 with an sr20de. I'm fixing it and when I was going to replace the crank angle sensor I found a few dodgy wires going to it. Big one is this wire that has no insulation, can't be factory but someone has extended it a little then wrapped it round the rest and taped up.. Not sure what it does but CAS connector is 4 pin and the connector it goes to is 5 (unused therefore). 

 

 

As the connector is the same for various other sr2des, some rbs, I've looked at wiring diagrams for said cars (bugger all for Serenas online) and still nothing. 

 

I'm guessing it could be for troubleshooting? But the cut and tape job surely can't be factory. And I'm gonna fit wires of the same gauge to the CAS replacing the thin ones currently connected to it

[pl0x]

Possibly shielding wire, but most shielding I've seen is around the sensor wire. CAS is something that would need shielding.

Unsure if factory or not, but those crimps are used in factory looms.

Being unused could make sense for a shield (grounded at the ecu).