No Communication On Class II Data Link

Diagnostic Chart:

Schematic:

If communications cannot be established with any modules, (BCM, PCM, SDM, or EBTCM) the fault is related to Class II link. Types of faults that will affect communications could be a short-to-ground, short-to-voltage, and open circuit between data link connector (DLC) and BCM. Internal controller faults could also cause communications errors on data link. Because Class II link is wired in a ring configuration, an open circuit, except between DLC and BCM, will not affect communications with BCM.