Communication For Initializing Impossible

Detecting condition: 

• Defective harness connector
• Power supply circuit malfunction
• Defective MFD
• Defective CAN communication circuit
• Defective Subaru Select Monitor

Trouble symptom: 

Communication is impossible between MFD and Subaru Select Monitor.

Wiring diagram: 

• Multi-function display (MFD) system Ref. to WIRING SYSTEM>Multi-function Display (MFD) System>WIRING DIAGRAM
• CAN communication system Ref. to WIRING SYSTEM>CAN Communication System>WIRING DIAGRAM

Courtesy of SUBARU OF AMERICA, INC.

1. CHECK IGNITION SWITCH  .

   Check the ignition switch.

   Is the ignition switch ON?

   Yes: Go to  2

   No: Turn the ignition switch to ON, and select «Multi-function Display» using Subaru Select Monitor.

2. CHECK BATTERY  .
   1. Turn the ignition switch to OFF.
   2. Check the battery. Ref. to STARTING/CHARGING SYSTEMS(STI)>Battery>INSPECTION . Ref. to STARTING/CHARGING SYSTEMS(EXCEPT FOR STI)>Battery>INSPECTION

   Is the check result OK?

   Yes: Go to  3

   No: Charge or replace the battery.

3. CHECK INSTALLATION OF MFD CONNECTOR  .

   Check the MFD connector.

   Is the MFD connector inserted until it is locked?

   Yes: Go to  4

   No: Insert the MFD connector to MFD until it is locked.

4. CHECK LAN SYSTEM  .

   Perform the diagnosis for LAN system. Ref. to LAN SYSTEM (DIAGNOSTICS)>Basic Diagnostic Procedure

   Is there any fault in LAN system?

   Yes: Perform the inspection according to the diagnosis for LAN system.

   No: Go to  5

5. CHECK SUBARU SELECT MONITOR COMMUNICATION  .
   1. Turn the ignition switch to ON.
   2. Check whether communication to MFD can be executed normally.

   Is communication with «Multi-function Display» possible?

   Yes: Using the Subaru Select Monitor, read DTC of «Multi-function Display». Ref. to MULTI-FUNCTION DISPLAY(DIAGNOSTICS)>Read Diagnostic Trouble Code (DTC) 

   No: Go to  7

6. CHECK SUBARU SELECT MONITOR  .

   Connect the Subaru Select Monitor to another vehicle to check whether the communication for initializing can be executed normally.

   Is communication for initializing possible?

   Yes: Go to  7

   No: Repair or replace the Subaru Select Monitor.

7. CHECK MFD POWER SUPPLY CIRCUIT (OPEN OR SHORT CIRCUIT)  .
   1. Turn the ignition switch to OFF.
   2. Disconnect the MFD connector.
   3. Turn the ignition switch to ON.
   4. Using a tester, measure the voltage between the MFD connector and chassis ground.

      Connector & terminal 

      (i122) No. 23 (+) - Chassis ground (-):

      (i122) No. 24 (+) - Chassis ground (-):

   Is the voltage 10 - 15 V?

   Yes: Go to  8

   No: Repair the open or short circuit of harness or the poor contact of connector between the MFD and the battery.

8. CHECK MFD GROUND CIRCUIT (OPEN)  .
   1. Turn the ignition switch to OFF.
   2. Measure the resistance between MFD connector and chassis ground.

      Connector & terminal 

      (i122) No. 21 - Chassis ground:

   Is the resistance less than 10 Ω?

   Yes: Go to  9

   No: Repair the open circuit of the MFD ground circuit or poor contact of connector.

9. CHECK POOR CONTACT OF CONNECTOR  .

   Check for poor contact in MFD power supply, ground circuit and data link connector.

   Is there poor contact?

   Yes: Repair the poor contact.

   No: Replace the MFD. Ref. to INSTRUMENTATION/DRIVER INFO>Multi-function Display (MFD)