Diagnostic Procedure For Subaru Select Monitor Communication: Inspection

Trouble symptom: 

Cannot communicate with [Multi-Function Display].

Detecting condition: 

• Defective harness connector
• Power supply circuit malfunction
• Defective MFD
• Defective CAN communication circuit
• Defective 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 the [Multi-Function Display] using the Subaru Select Monitor.

2. CHECK BATTERY  .
   1. Turn the ignition switch to OFF.
   2. Check the battery. Ref. to STARTING/CHARGING SYSTEMS (H4DO)>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 into the MFD until it locks?

   Yes  : Go to  4 .

   No  : Be sure to insert the MFD connector into the 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  : Read the DTC of [Multi-Function Display] using the Subaru Select Monitor. Ref. to MULTI-FUNCTION DISPLAY (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .

   No  : Go to  6 .

6. CHECK SUBARU SELECT MONITOR  .

   Connect the Subaru Select Monitor to another vehicle to verify that 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 and terminal 

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

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

   Is the voltage 10 - 16 V?

   Yes  : Go to  8 .

   No  : Repair the open or short circuit of harness, or poor contact of connector.

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

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

   Is there poor contact?

   Yes  : Repair the poor contact.

   No  : Replace the MFD. Ref. to INSTRUMENTATION/DRIVER INFO>MULTI-FUNCTION DISPLAY (MFD) .