The two generation sensors are not interchangeable mechanically or electrically.
To test:
ABS 2 sensor:
Wound coil
Resistance should read approx 130 ohms.
Scope attached directly across leads you see should a sine wave on a scope in the 4-7v range with a varying frequency depending on wheel speed. approx 0-120hz spun by hand.
ABS 3 sensor (servo):
Electronic (suspect hall sensor)
Resistance method won't work.
12vdc+ thru a 1k ohm resistor to pin 2 of the sensor connector. Pin 1 goes to 12vdc-.
Attach scope leads across the resistor. you see should a square wave on a scope in the 4-7v range with a varying frequency depending on wheel speed. approx 0-120hz spun by hand
On both types you can also monitor frequency on a good quality DVM set to Low volts AC HZ if you don't have a scope.