Diagnostic Procedure for Subaru Select Monitor Communication: Inspection

When communication with DCM is impossible

Detecting condition  :

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

Trouble symptom  :

Communication is impossible between DCM and Subaru Select Monitor.

• Telematics Ref. to WIRING SYSTEM>TELEMATICS SYSTEM>WIRING DIAGRAM .
• CAN communication system Ref. to WIRING SYSTEM>CAN COMMUNICATION SYSTEM>WIRING DIAGRAM .

Courtesy of SUBARU OF AMERICA, INC.

1. CHECK SUBARU SELECT MONITOR COMMUNICATION  .

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

   Does the Subaru Select Monitor communicate normally?

   Yes  : GO TO  2.

   No  : Repair or replace the Subaru Select Monitor.

2. 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 1 Ω?

   Yes  : Check for poor contact of the data link connector, and repair a fault, if any.

   When no fault is found, GO TO  3.

   No  : Repair the harness and connector.

3. 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  4.

   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 No. 3) 
4. CHECK FUSE  .
   1. Turn the ignition switch to OFF.
   2. Remove a fuse from the fuse box.
   3. Check the fuse. Ref. to WIRING SYSTEM>TELEMATICS SYSTEM>WIRING DIAGRAM .

   Is the check result OK?

   Yes  : GO TO  5.

   No  : Replace the fuse. If the replaced fuse blows out easily, repair the ground short circuit in harness between the DCM and fuse.

5. CHECK DCM POWER SUPPLY CIRCUIT (OPEN)  .
   1. Disconnect the DCM connector.
   2. Turn the ignition switch to ON.
   3. Using a tester, measure the voltage between DCM connector and chassis ground.

      Connector & terminal 

      (i105) No. 8 (+) - Chassis ground (-)  :

      (i105) No. 10 (+) - Chassis ground (-)  :

   Is the voltage 10 V or more?

   Yes  : GO TO  6.

   No  : Check for open or short circuit in the harness between the DCM and fuse.

6. CHECK DCM GROUND CIRCUIT (OPEN)  .
   1. Turn the ignition switch to OFF.
   2. Using a tester, measure the resistance in the harness between DCM connector and chassis ground.

      Connector & terminal 

      (i105) No. 14 - Chassis ground  :

   Is the resistance less than 1 Ω?

   Yes  : GO TO  7.

   No  : Check for open or short circuit between DCM connector and chassis ground.

7. CHECK LAN SYSTEM  .

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

   Is the check result OK?

   Yes  : GO TO  8.

   No  : Repair it according to the diagnosis for LAN system. Ref. to LAN SYSTEM (DIAGNOSTICS)>BASIC DIAGNOSTIC PROCEDURE>PROCEDURE .

8. CHECK TELEMATICS  .
   1. Turn the ignition switch to ON.
   2. Using the Subaru Select Monitor, communicate with [Telematics].

   Is communication possible?

   Yes  : Even if DTC is displayed, the circuit has returned to a normal condition at this time.

   Reproduce the failure, and then perform the diagnosis again.

   NOTE: In this case, temporary poor contact of connector, temporary open or short circuit of harness may be the cause.

   No  : Replace the DCM. Ref. to ENTERTAINMENT & MONITORING>DATA COMMUNICATION MODULE .