When asking for technical help at the very least let us know the version of firmware you are running.Cliff's Calibration (Mapping) Guide is a MUST READ: http://www.vemssupport.com/forum/index.php/topic,97.0.html
Hy, my car has "speedo sender" on tranny. it has two pins.Managed to get some info on alfabb forum: "that the output of the speedometer sensor is a square wave of approx. 8V amplitude (I think it was), about 50% duty cycle, with the frequency picking up to several hundred hertz at 'high' speeds.But it might be better to tap abs wheel sensor also two wire. It's 1988 bosch abs system similiar to bmw e30 or vauxhall...
add 10nF, recommended.If you use VR sensor, you will need decoder with LM1815 chip.