Diagnostic data link: Notes

The ABS control module is not connected to a bus. Diagnostic communication takes place over a lead from pin 11 of the ABS control module to pin 8 of the data link connector (diagnostic socket) and from there direct to the diagnostic tool.

The diagnostic tool communicates digitally and serially with the ABS. Digitally means that the difference in voltage between the lead and earth has two values, in this case about 0 V and B+. The information is coded so that different combinations of 0 V and B+ pulses have different meanings.

Serially means that the information is sent in "packets" one after the other in very quick succession.