Diagnostic Procedure For Subaru Select Monitor Communication: Inspection

Detecting condition: 

Defective harness connector

Trouble symptom: 

Communication is impossible between VDC and Subaru Select Monitor.

Wiring diagram: 

Vehicle dynamics control system Ref. to WIRING SYSTEM>VEHICLE DYNAMICS CONTROL SYSTEM .

Courtesy of SUBARU OF AMERICA, INC.

1. CHECK IGNITION SWITCH  .

   Is the ignition switch ON?

   Yes  : Go to  2 .

   No  : Turn the ignition switch to ON, and select the [Brake Control] using the Subaru Select Monitor.

2. CHECK BATTERY  .
   1. Turn the ignition switch to OFF.
   2. Measure the battery voltage.

   Is the voltage 11 V or more?

   Yes  : Go to  3 .

   No  : Charge or replace the battery.

3. CHECK BATTERY TERMINAL  .

   Is there poor contact at battery terminal?

   Yes  : Replace or tighten the battery terminal.

   No  : Go to  4 .

4. CHECK INSTALLATION OF VDCCM&H/U CONNECTOR  .

   Turn the ignition switch to OFF.

   Is the VDCCM&H/U connector inserted into VDCCM&H/U until the clamp locks onto it?

   Yes  : Go to  5 .

   No  : Insert VDCCM&H/U connector into VDCCM&H/U.

5. CHECK LAN SYSTEM  .

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

   Is the check result OK?

   Yes  : Go to  6 .

   No  : Perform the diagnosis for LAN system.

6. CHECK SUBARU SELECT MONITOR COMMUNICATION  .
   1. Turn the ignition switch to ON.
   2. Check whether communication to VDC system can be executed normally.

   Is the [Select Function] screen displayed?

   Yes  : Check the DTC in VDC system. Ref. to BRAKE CONTROL (DIAGNOSTICS)>DIAGNOSTIC TROUBLE CODE (DTC) .

   No  : Go to  7 .

7. 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  8 .

   No  : Repair or replace the Subaru Select Monitor.

8. CHECK POWER SUPPLY CIRCUIT  .
   1. Turn the ignition switch to ON. (Engine OFF)
   2. Measure the ignition power supply voltage between VDCCM&H/U connector and chassis ground.

      Connector and terminal 

      (B310) No. 1 (+) - Chassis ground (-):

      (B310) No. 30 (+) - Chassis ground (-):

      (B310) No. 36 (+) - Chassis ground (-):

   Is the voltage 10 - 15 V?

   Yes  : Go to  9 .

   No  : Repair open circuit in harness between VDCCM&H/U and battery.

9. CHECK HARNESS CONNECTOR BETWEEN VDCCM&H/U AND CHASSIS GROUND  .
   1. Turn the ignition switch to OFF.
   2. Disconnect the connector from the VDCCM&H/U.
   3. Measure the resistance of harness between VDCCM&H/U connector and chassis ground.

      Connector and terminal 

      (B310) No. 14 - Chassis ground:

      (B310) No. 46 - Chassis ground:

   Is the resistance less than 10 Ω?

   Yes  : Go to  10 .

   No  : Repair the open circuit of VDCCM&H/U ground circuit and poor contact of connector.

10. CHECK POOR CONTACT OF CONNECTOR  .

    Is there poor contact of control module power supply, ground circuit and data link connector?

    Yes  : Repair the connector.

    No  : Replace the VDCCM&H/U. Ref. to VEHICLE DYNAMICS CONTROL (VDC)>VDC CONTROL MODULE AND HYDRAULIC CONTROL UNIT (VDCCM&H/U) .