Scan Tool Will Not Communicate With Can Bus

NOTE:

This procedure diagnoses CAN Bus circuits after the Security Gateway (SGW) Module.

NOTE:

If the vehicle operates, but the scan tool topology screen indicates all modules on a CAN Bus do not communicate, proceed to SCAN TOOL DOES NOT COMMUNICATE WITH VEHICLE. Refer to DIAGNOSIS AND TESTING .

NOTE:

Due to the loss of communication on the CAN Bus, multiple modules may not communicate on the network and certain U-code DTCs, such as CAN BUS OFF, CAN BUS MISSING MESSAGE or CAN BUS NO SIGNAL, may not be displayed on the scan tool until the cause of the fault is repaired.

If the vehicle does not operate properly and the scan tool topology screen indicates modules on a CAN Bus do not communicate, perform the appropriate Body Control Module (BCM) CAN BUS OFF, CAN BUS MISSING MESSAGE or CAN BUS NO SIGNAL U-code diagnostic procedure for the CAN Bus being diagnosed. Refer to DIAGNOSIS AND TESTING .