Hi Shane

I agree with Chris, poke all three wires and report your findings.

Also, you need to start scoping known good cars in your spare time to get a feel for the scope and see what signals different types of sensors give out and why?

What scope have you got?

When I got my scope I had the shock of my life
I realised I basically didn't know sh@t about how the ECU managed the engine and the importance of the signals from the sensors or even what signals would be sent from different sensors.

There are loads of training courses (I know time and money)
But, to be honest, to get the basics of sensors and their signals, so you can hook up and test confidently with your scope, I would suggest getting a couple of cheap books off Amazon or similar.

I would reccomend the book I first bought for basic electrics was:
How to diagnose and repair automotive electrical systems by Tracy Martin

It is very easy reading and packed with info.

The Hiller's automotive books will catapult you forwards with a deeper knowledge of the sensors and the signals they output.

There are plenty of other books that you may prefer these are just a couple that I read and can vouch for.

Lastly,
Forgive me if I have mis-read your post and this post comes across patronising that is not how it was intended!

hth
James