Problem with my auto gearbox after an oil change

[Radnor-steve]

Last night I decided to change the gearbox oil.... I drained all the oil out and removed the sump to gain access to the filter. Change the filter and cleaned any oil left behind with a clean sloth. Put it all back together and refilled with new oil intill it started to overflow out...( as shown on YouTube)

Tried to drive the off the ramp and it would not move forward at low revs. I slowly increase the revs until it moved / jumped forward at 1500rpm. It is the same if I put it in reverse.
Once I am moving the car drives really nice, smooth gear changes and kicks down ok....

[Gazwould]

What oil did you use?

[Radnor-steve]

Not sure without looking, I bought it as a kit... just put it on my computer (Hella macs 46) it saying that it is the RPM gearbox sensor fault....

[Radnor-steve]

Does anybody know why.... or were abouts the the sensor is!!!!!