Communication For Initializing Impossible

When communication with Data Communication Module is impossible

Detecting condition: 

• Defective harness connector
• Power supply circuit malfunction
• Defective Data Communication Module
• Defective CAN communication circuit
• Defective Subaru Select Monitor

Trouble symptom: 

Communication is impossible between Data Communication Module and Subaru Select Monitor.

Wiring diagram: 

Telematics Ref. to WIRING SYSTEM>Telematics System>WIRING DIAGRAM

Courtesy of SUBARU OF AMERICA, INC.

1. CHECK FUSE  .
   1. Turn the ignition switch to OFF.
   2. Check the fuse of the Data Communication Module.

   Is the check result OK?

   Yes: Go to  2

   No: Replace the fuse. If the replaced fuse blows out easily, repair the ground short circuit in harness between the fuse - Data Communication Module connector.

2. CHECK HARNESS (OPEN CIRCUIT)  .
   1. Disconnect the Data Communication Module connector.
   2. Turn the ignition switch to ON.
   3. Using a tester, measure the voltage between Data Communication Module connector (harness side) and the chassis ground.

      Connector & terminal 

      (i270) No. 8 (+) - Chassis ground (-):

      (i270) No. 10 (+) - Chassis ground (-):

   Is the voltage 10 V or more?

   Yes: Go to  3

   No: Repair the open circuit in the wiring harness between fuse and Data Communication Module connector.

3. CHECK HARNESS (OPEN CIRCUIT)  .
   1. Turn the ignition switch to OFF.
   2. Using a tester, measure the resistance between Data Communication Module connector (harness side) and the chassis ground.

      Connector & terminal 

      (i270) No. 14 - Chassis ground:

   Is the resistance 1 Ω or less?

   Yes: Go to  4

   No: Repair the open circuit in the wiring harness between fuse and Data Communication Module connector.

4. CHECK LAN SYSTEM  .

   Inspect LAN system. Ref. to LAN SYSTEM (DIAGNOSTICS)>Basic Diagnostic Procedure

   Is the check result OK?

   Yes: Go to  5

   No: Perform the inspection according to the diagnosis for LAN system.

5. CHECK TELEMATICS  .

   Using the Subaru Select Monitor, communicate with the telematics system.

   Is communication possible?

   Yes: The circuit has returned to a normal condition at this time. Reproduce the failure, and then perform the diagnosis again.

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

   No: Replace the Data Communication Module. Ref. to ENTERTAINMENT & MONITORING>Data Communication Module