Communication For Initializing Impossible

DIAGNOSIS: 

Defective harness connector

TROUBLE SYMPTOM: 

Subaru Select Monitor communication failure

WIRING DIAGRAM: 

• Non-turbo model

  CVT control system Ref. to WIRING SYSTEM > CVT Control System >-->  NON-TURBO MODEL  .

Fig 1: TCM - Wiring Diagram (Non-Turbo Model)

Courtesy of SUBARU OF AMERICA, INC.

• Turbo model

  CVT control system Ref. to WIRING SYSTEM > CVT Control System >-->  TURBO MODEL  .

Fig 2: TCM - Wiring Diagram (Turbo Model)

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 transmission 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: Repair or tighten the battery terminal.

   No: Go to  4.

4. CHECK INSTALLATION OF TCM CONNECTOR  .

   Turn the ignition switch to OFF.

   Is the TCM connector inserted into the TCM until the clamp locks?

   Yes: Go to  5.

   No: Insert the TCM connector to TCM.

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 transmission system can be executed normally.

   Is the system name displayed on Subaru Select Monitor?

   Yes: Check DTC of TCM. Ref. to CONTINUOUSLY VARIABLE TRANSMISSION (DIAGNOSTICS) > Read Diagnostic Trouble Code (DTC) .

   No: Go to  7.

7. CHECK POWER SUPPLY CIRCUIT  .
   1. Turn the ignition switch to ON. (Engine OFF)
   2. Measure the ignition power supply voltage between TCM connector and chassis ground.

      Connector & terminal 

      (B54) No. 34 (+) - Chassis ground (-):

      (B54) No. 8 (+) - Chassis ground (-):

      (B54) No. 24 (+) - Chassis ground (-):

      (B54) No. 41 (+) - Chassis ground (-):

      (B54) No. 40 (+) - Chassis ground (-):

   Is the voltage 10 - 13 V?

   Yes: Go to  8.

   No: Repair the open circuit of harness between TCM and battery.

8. CHECK HARNESS CONNECTOR BETWEEN TCM AND CHASSIS GROUND  .
   1. Turn the ignition switch to OFF.
   2. Disconnect the connector from TCM.
   3. Measure the resistance of harness between TCM connector and chassis ground.

      Connector & terminal 

      (B54) No. 42 - Chassis ground:

   Is the resistance less than 10 Ω?

   Yes: Go to  9.

   No: Repair the open circuit of the TCM ground circuit and poor contact of connector.

9. 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: Check the TCM.