Is their a functional malfunction?

• Repair this first.
• Note the codes and clear the DTC memories of all control modules, See ERASE DTC MEMORY (FUNCTION 05) AND END OUTPUT (FUNCTION 06)  .
• Press the 0 and 6 buttons for the "End Output" function and confirm the entry using the Q button.
• End Output from the scan tool using the "End Output" function.
• Repair the functional malfunctions using the DTC table in the corresponding workshop manuals.

Once you have eliminated all functional malfunctions:

• If communication between the control modules is still disrupted, you will have to check the bus lines.