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 .

Courtesy of SUBARU OF AMERICA, INC.

CAUTION:

Before performing diagnosis, refer to "CAUTION" in "General Description". Ref. to BODY CONTROL/COMMUNICATION SYSTEM>GENERAL DESCRIPTION>CAUTION .

CHECK POWER SUPPLY CIRCUIT .
1. Connect the interface for Subaru Select Monitor to the data link connector. COMMON (DIAGNOSTICS)>DATA LINK CONNECTOR
2. Does the interface for Subaru Select Monitor turn on?
  Connector & terminal
  
  Yes: Go to 4 .
  
  No: Go to 2
CHECK POWER SUPPLY CIRCUIT .
1. Turn the ignition switch to ON. (Engine OFF)
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)
CHECK HARNESS CONNECTOR BETWEEN Front relay control module AND CHASSIS GROUND .
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.
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.