Accessories and Optional Equipment: Service Precautions
PRECAUTIONS DURING MMCS SERVICEBEFORE REMOVING THE BATTERY
MMCS stores a large volume of information which is input at the discretion of customers. The memory of each information becomes as follows when the battery terminal is removed. Therefore, before removing the battery, the recording of preset channels is necessary. Depending on the time period of battery removal, the current location, destination, and others of the navigation function must be recorded.
DIAGNOSIS TIPS CONCERNING THE ENTIRE SYSTEM
1. When a trouble symptom occurs with which two or more system functions become abnormal simultaneously, the communication error between each unit is strongly suspected. Therefore, check the symptom with the service function link and communication check of the diagnosis service function.
2. When an error code 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. When the wiring harness connectors are engaged correctly, check the wiring harness. If the wiring harness is in good condition, replace relevant components. At this time, record the error code and service function data.
NOTE: If a system communication related failure is suspected, carry out the troubleshooting.
DIAGNOSIS TIPS WHEN ONLY SPECIFIC FUNCTION(S) IS DEFECTIVE
1. When an abnormality occurs only to the specific function, perform the hard switch check of service function audio check.
2. When the switch function is normal, check that the wiring harness connectors related to the specific function are engaged correctly. If a failure is found, repair the connectors and check the trouble symptom again.
3. When the wiring harness connectors are engaged correctly, check the wiring harness. If the wiring harness is in good condition, replace relevant components, which controls that function.
NAVIGATION FUNCTION DIAGNOSIS TIPS
1. The vehicle position accuracy of navigation function has a limitation due to its operation principles. Therefore, depending on the contents of customer claims, the system itself may be normal.
Before performing the diagnosis, listen to the use status and driving location of the customer sufficiently. When a judgment can be made that it is not a system abnormality, explain to the customer the navigation function operation principle and how to use the function.
2. When the system abnormality is recognized, perform the check according to the symptom procedures of troubleshooting.