Is 4.3 V enough to power abs sensors?

[Rawze]

Replace the sensor if it is old would be my first choice. Next would be to clean up all the plugs and connectors + ensure no pins were tarnished. Then perhaps use an ohm meter on the wires for the circuit while they were disconnected at both ends + check for resistance to ground on each wire. Last would be to disconnect the wiring at both ends completely, ground all pins at one end, then load test the wires with a tail light for a car fed by +12v. Sometimes wires have to be load tested to find corrosion or excess resistance. The brightness of a tail light bulb will often reveal weak connections visually.