If a malfunction exists

Repair this malfunction first:
Make a note of any codes and erase the DTC memories of all control modules. See ERASING DTC MEMORY .
Press buttons -0- and -6- for the function "End Output" and confirm entry with the -Q- button.
End the output on the scan tool with the function "End Output". See ENDING OUTPUT .
Repair the malfunctions as described in the DTC table.
When all malfunctions have been repaired:
If communication between the control modules is still not working properly, test the bus wires.