Cutlass V6-191 3.1L VIN M SFI (1998)
Information Bus: Component Tests and General Diagnostics
The Data Link Connector (DLC) is provided to enable communications. with specific control modules using an external scan tool. The use of the scan
tool in control module diagnostics is described in the Driveability and Emissions, Supplemental Inflatable Restraints, Anti lock Brakes, and Computer
System Diagnosis service manual. There are two data lines that can be accessed with a scan tool. The Serial Data Line-UART (800 circuit) allows the
scan tool to communicate with the Sensing Diagnostic Module.
The Serial Data Line-Class 2 (1807 circuit) allows internal communications between the Body Function Controller (BFC), Electronic Brake Control
Module (EBCM), and Powertrain Control Module (PCM), as well as with the external scan tool. A module to module communication failure due to
wiring problems may also result in communication failure with the scan tool.
