Okay I am 95% done with my megasquirt 2 VB3 install on my S5 streetport in my S4 chassis and I am using an S5 TB with S5 TPS for the wide range TPS signal but I cant find anywhere what wires go where.

I am only going to wire the wideband TPS signal and the three wires are:

Blue
Yellow
Red

which one is the 5v ref? which one is the ground? The FSM doesnt say, it just shows how to test each range.

 

well, the 5V and ground will always have the same resistance between them, regardless of the plunger position. The signal therefore will be the one that has changing resistance with the other two as the plunger moves.

Now that you know which one the signal wire is, IIRC, when the throttle is closed, the resistance between ground and the signal wire will be much lower than the resistance between the signal wire and 5V. As the throttle opens, these resistances will get closer together and then swap, so that at WOT the resistance between the signal and 5V is much lower than between sig and ground. This will tell you which is 5V and which is ground.

One thing to look out for with the stock plunger is that at WOT, i've noticed enough vibration to cause it to jitter around a bit, potentially triggering the accel-based enrichments and enleanments.

 

figured it out:


TPS side harness ----------------- Car side/MS harness
Color
Blue ------------------------------------------- Ground
Red -------------------------------------------- VREF (grey wire)
Yellow --------------------------------------- Blue wire