Communication For Initializing Impossible

Detecting condition: 

Defective harness connector

Trouble symptom: 

Communication is impossible between VDC and Subaru Select Monitor.

Wiring diagram: 

Vehicle dynamics control system Refer to WIRING SYSTEM (IMPREZA MODEL)>VEHICLE DYNAMICS CONTROL SYSTEM . Refer to WIRING SYSTEM (CROSSTREK MODEL (EXCEPT FOR HEV))>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 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 VDC CONTOL MODULE & H/U CONNECTOR. 

   Turn the ignition switch to OFF.

   Is the VDC Contol Module & H/U connector inserted into VDC Contol Module & H/U until the clamp locks onto it?

   Yes:  Go to  5.

   No:  Insert VDC Contol Module & H/U connector into VDC Contol Module & H/U.

5. CHECK LAN SYSTEM. 

   Perform the diagnosis for LAN system using the Subaru Select Monitor. Refer to LAN SYSTEM (DIAGNOSTICS) (EXCEPT FOR HEV)>BASIC DIAGNOSTIC PROCEDURE .

   Is DTC of CAN communication displayed?

   Yes:  Perform the diagnosis according to DTC. Refer to LAN SYSTEM (DIAGNOSTICS) (EXCEPT FOR HEV)>DIAGNOSTIC TROUBLE CODE (DTC)>LIST .

   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. Refer 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 VDC Contol Module & H/U connector and chassis ground.

      Connector & terminal 

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

      (B310) No. 6 (+) - Chassis ground (-):

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

   Is the voltage 10 - 15 V?

   Yes:  Go to  9.

   No:  Repair open circuit in harness between VDC Contol Module & H/U and battery.

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

      Connector & terminal 

      (B310) No. 13 - Chassis ground:

   Is the resistance less than 10 Ω?

   Yes:  Go to  10.

   No:  Repair the open circuit of VDC Contol Module & 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 VDC Contol Module & H/U. Refer to VEHICLE DYNAMICS CONTROL (VDC)>VDC CONTROL MODULE AND HYDRAULIC CONTROL UNIT (VDCCM & H/U) .