Malibu V6-3.1L VIN J (2002)
Information Bus: Symptom Related Diagnostic Procedures
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 (DTC's) may 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 engine will not start when there is a total malfunction of the Class 2 serial data circuit while the engine is not running.
The Class 2 serial data circuit for the EBCM and PCM are on a common terminal on the Junction Block-Left I/P.
The Class 2 serial data circuit for the BCM and SDM are on a common terminal on the Junction Block-Left I/P.
The Class 2 serial data circuit for the DLC and Radio are on a common terminal on the Junction Block-Left I/P.
TEST DESCRIPTION
Steps 1-8