2002 Mercury Marquis GRAND MARQUIS 2002 ABS AND BRAKE LIGHT

HI, I HAVE A GRAND MARQUIS 2002, ABS AND BRAKE WARNING LIGHTS ALWAYS ON, THEY DON'T OF WHEN CAR IS RUNNING, I CHECK FUSES CONNECTORS, ALL OK, BUT WHEN IS CONNECT AN ABS SCAN TOOL THERE IS NO COMMUNICATION WITH THE ABS MODULE, I CHECK ELECTRICAL CONNECTIONS IN THE ABS MODULE CONNECTOR AND ALL OK VOLTAGES AND GROUND, I TEST THE RESISTANCE OF THE ABS WHEEL SENSOR AND ALL OK, IS THE PROBLEM THE ABS ELECTRONIC MODULE? THANKS.
RAMON V.