Data Link Connector (DLC)
The data link connector (DLC) terminal 2 contains the  class 2
serial data link.
The DLC also provides a power source and Signal Ground for the scan tool as
follows:
|     •  | Battery voltage at the DLC terminal 16 (circuit 40) | 
 
|     •  | Power Ground at terminal 4 (circuit 150) | 
 
|     •  | Signal Ground at terminal 5 (circuit  451) | 
 
Class 2 Serial Data Link
The class 2 serial data link allows the following modules to communicate  with
each other:
|     •  | The body control module (BCM) | 
 
|     •  | Digital radio receiver (DRR) | 
 
|     •  | The electronic brake control module (EBCM) | 
 
|     •  | The instrument panel cluster (IPC) | 
 
|     •  | The powertrain control module (PCM) | 
 
|     •  | The inflatable restraint sensing and diagnostic module (SDM) | 
 
|     •  | Vehicle communication interface module (VCIM) | 
 
The class 2 serial data link allows a scan tool to communicate  with
the above modules for diagnostic and testing purposes.