That wire coming from the ECU is merely a signal wire instructing the instrument cluster module to energize the low oil lamp on the dash. Doubt you'll be able to use it.
The problem with the factory low oil light is it’s set at something like 7psi. Too little, too late…
Before the AiM install, I used this configurable pressure gauge from Speedhut:
https://speedhut.com/gauge-applicati...psi-w-warning/
A very high quality gauge that was far better than VDO type gauges.
I've also simply plumbed in a 15 psi pressure switch and had a big red light on the dash on my previous car. Worked, but not elegant. I’ve used higher switches, like 20 psi, but found they frequently came on in certain points on track. Proved too distracting. Also a bit disconcerting that oil pressure does see dips with the wet sump system. Dry sump FTW!
With the AiM dash you can set the warning using multiple variables, like warn me if pressure goes below 40 psi when over 6,000 rpm. Since my dry sump pressure is rpm dependent, this works great.