Communication For Initializing Impossible

Detecting condition: 

Defective harness connector

Trouble symptom: 

Communication is impossible between VDC and Subaru Select Monitor.

WIRING DIAGRAM  :

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 VDC 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  .

   Perform the diagnosis for LAN system. Ref. to LAN SYSTEM (DIAGNOSTICS)>BASIC DIAGNOSTIC PROCEDURE .

   Is there any fault in LAN system?

   Yes: Perform the diagnosis according to DTC for LAN system. Ref. to LAN SYSTEM (DIAGNOSTICS)>LIST OF DIAGNOSTIC TROUBLE CODE (DTC) .

   No: Go to  6.

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)>Read 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 & terminal

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

      (B310) No. 25 (+) - Chassis ground (-):

      (B310) No. 28 (+) - 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 & terminal

      (B310) No. 38 - 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) .