Diagnostics communication: Diagnostics
If communication with the system cannot be established, the fault could either be in the car or the diagnostic tool. If the diagnostic tool cannot establish communication with the same system in another car, then the fault is in the car.
First check that the control module is active - it should test the ABS warning lamps as soon as the ignition is switched on. If the control module is active, then the fault can probably be traced to the lead between it and the data link connector.