Here is part of a GM TSB on ABS false activation "Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in the General Information sub-section of the Service Manual (SI Document ID #899664). Disconnect both the front wheel speed sensor (WSS) connectors at the frame and harness. Place a Digital Volt Meter (DVM) across the terminals of each WSS connector. Rotate the wheel clockwise approximately one revolution per second. The minimum reading should be at least 350 ACmV's. If the reading is less than 350 ACmV's, remove the wheel speed sensor. Refer to the applicable Wheel Speed Sensor Replacement procedure in the ABS sub-section of the Service Manual. Plug the WSS bore in order to prevent debris from falling into the hub during service. Clean the WSS mounting surface on the hub to remove any rust or corrosion using a wire brush, or equivalent. Important Make sure that the sensor sits flat on the hub. Check the sensor flange against a straight edge to ensure flatness. If the sensor flange is distorted, replace the sensor. Apply a thin layer of bearing grease to the hub surface and sensor O-ring prior to sensor installation. Use ONLY Wheel Bearing Lubricant, P/N 01051344 (Canadian P/N 993037). Install either the original sensor or a new one in the hub. Ensure that the sensor is seated flush against the hub. Refer to the applicable Wheel Speed Sensor Replacement procedure in the ABS sub-section of the Service Manual. Place the DVM across the sensor terminals and recheck the voltage while rotating the wheel. The voltage should now read at least 350 ACmV's" Note that GM asks for wheel bearing grease to be used when inserting the ABS ssensor into its mounting hole. Wabco also asks for a mineral-based lubricant to be used with its ABS wheel speed sensors. I have been ignoring Wabco's suggestion and have been using dielectric grease on the medium duty trucks at work. Yesterday I came across the GM TSB that I posted above and now I am really curious as to why a mineral-based lubricant is specifically called for for ABS sensors.