Diagnostic Procedure for Subaru Select Monitor Communication: Inspection

Trouble symptom: 

Communication with Front relay control module is impossible.

Detecting condition: 

• Defective harness connector
• Power supply circuit malfunction
• Front relay control module malfunctioning
• Defective CAN communication circuit
• Defective Subaru Select Monitor

Wiring diagram: 

• CAN communication system Ref. to WIRING SYSTEM>CAN COMMUNICATION SYSTEM>WIRING DIAGRAM .
• Headlight system Ref. to WIRING SYSTEM>HEADLIGHT SYSTEM>WIRING DIAGRAM .

Courtesy of SUBARU OF AMERICA, INC.

1. CHECK POWER SUPPLY CIRCUIT  .

   Connect the interface for Subaru Select Monitor to the data link connector. Ref. to COMMON (DIAGNOSTICS)>DATA LINK CONNECTOR .

   Does the interface for Subaru Select Monitor turn on?

   Yes:  Go to  4.

   No:  Go to  2.

2. CHECK POWER SUPPLY CIRCUIT  .
   1. Turn the ignition switch to ON.
   2. Using the tester, measure the voltage between data link connector and chassis ground.

      Connector & terminal 

      (i221) No. 8 (+) - Chassis ground (-):

      (i221) No. 16 (+) - Chassis ground (-):

   Is the voltage 10 V or more?

   Yes:  Go to  3.

   No:  Repair the power supply circuit.

   NOTE: In this case, repair the following item:

   • Open or ground short circuit of harness between battery and data link connector
   • Blown out of fuse (M/B No. 2, F/B fuse No. 3)
3. CHECK HARNESS BETWEEN DATA LINK CONNECTOR AND CHASSIS GROUND (OPEN)  .
   1. Turn the ignition switch to OFF.
   2. Using the tester, measure the resistance between data link connector and chassis ground.

      Connector & terminal 

      (i221) No. 4 - Chassis ground:

      (i221) No. 5 - Chassis ground:

   Is the resistance less than 5 Ω?

   Yes:  Check for poor contact of the data link connector, and repair a fault, if any. When no fault is found, Go to  4.

   No:  Repair the harness and connector.

4. CHECK INSTALLATION OF Front relay control module CONNECTOR  .

   Turn the ignition switch to OFF.

   Is the Front relay control module connectors (B68, B69) inserted into the Front relay control module until they lock?

   Yes:  Check the LAN system. Ref. to LAN SYSTEM (DIAGNOSTICS)>BASIC DIAGNOSTIC PROCEDURE .

   No:  Insert the Front relay control module connector to Front relay control module. Repair the connector if the connector is faulty.