Just got the NVH system and am trying it out on a car without a data link connector- 1992 300TE Mercedes. Will any rpm signal work? - I have two choices on the 9 pin diagnostic connector under the hood, Pin 1 rpm signal 0-12volts, 4 pulses per revolution or pins 7 and 8 are from the crank sensor, I think it is just a raw crank sensor.
Thanks, Lars