Century V6-3.1L VIN J (2005)
Information Bus: Testing and Inspection
Scan Tool Does Not Communicate With Class 2 Device
SCAN TOOL DOES NOT COMMUNICATE WITH CLASS 2 DEVICE
CIRCUIT DESCRIPTION
Modules connected to the class 2 serial data circuit monitor for serial data communications during normal vehicle operation. Operating information
and commands are exchanged among the modules. Connecting a scan tool to the DLC allows communication with the modules for diagnostic
purposes.
Diagnostic trouble codes (DTCs) may be set due to this symptom and during this diagnostic procedure. Complete the diagnostic procedure in order to
ensure all the DTCs are diagnosed and cleared from memory.
DIAGNOSTIC AIDS
The body control module (BCM) detects the ignition switch position and sends the appropriate power mode message to the other modules. The BCM
must be connected to the class 2 serial data circuit for any other module to communicate with the scan tool.
TEST DESCRIPTION
