ABS Wheel sensor measurement

[Camelman]

The ABS light has been on constantly for a few weeks now, along with the brake warning light and the 4WD light. I decided to check all the wheel sensors and connectors this weekend.
Found that the rear sensors were full of grease!! Is this normal?
Made measurements of all the sensors with a multimeter and found that
LHS Rear - 242K ohms
RHS Rear - 440k ohms
LHS & RHS Fronts - 2.3M ohms?

Looks to me like both front sensors are Open circuit!!
Measured all of the wires to each sensor plug and there are no open circuits.

What is a normal sensor Resistance?

 

[4 naving]

The grease is normal but I have no idea on the resistance readings. I wonder if the position of the reader ring on the axel has anything to do with the readings. Maybe jack up one and watch reading with slight position change. The teeth on the reader rings are about 1mm then a 1mm gap ect....

 

[Old.Tony]

Before jumping to any conclusions about the sensor, jack the wheel up, rotate it a little and watch the sensor reading. It might just be normal variations based on the wheel rotation.