Precautions on servicing MMCS

Prior to disconnecting the vehicle battery

Diagnosis tips concerning the entire system

  1. If at least two system functions are defective at the same time, it is possible that communication between the system components is abnormal. Check the system using the communication and wire connection check in the service mode.
  2. If an error is displayed, check that relevant wiring harness connectors are engaged correctly. If a failure is found, repair the connectors and check the trouble symptom again.
  3. If the wiring harness connectors are engaged correctly, check the wiring harness. If the wiring harness is in good condition, replace relevant component(s). Now the error code and the service mode data must be stored.
note If a system communication related failure is suspected, diagnose the system.

Diagnosis tips concerning the navigation function

  1. The precision of the GPS positioning is limited due to its operation principles. So, some of customer reports do not mean that the system is defective.
    Prior to troubleshooting, interrogate your customer about how the navigation system is used and where he/she drives. If you determine that the system is OK, explain to your customer about how the system works and how the customer should operate it.
  2. If the system is not OK, diagnose the system according to the trouble symptom chart.