if only life was that simple eh?
apparently on an auto its connected to the gear selector mechanism but on a manual the wiring connects to earth via a 510 ohm resistor somewhere. I've had a look around the box and gear sticks housing and cant see an appropriate wire or resistor.
apparently (again sorry) on a manual it needs the resistor to fool the ecu into thinking the car is in gear! so the ecu doesn't attempt to adjust the idle via the stepper motor.
I dont know this for a fact but it's just what I've read on other forums (fora?)
cheers
