LEMON Manuals: Even more car manuals for everyone
Home >> Subaru >> 2021 >> Crosstrek Hybrid >> Repair and Diagnosis >> External Pages >> Different car >> Section 4 (Automatic Transaxle (Diagnostics) (IMPREZA)) >> Diagnostic Procedure for Subaru Select Monitor Communication >> Communication For Initializing Impossible

Communication For Initializing Impossible

WARNING: This page is about a different car, the 2021 Subaru Impreza. However, it is still accessible from the selected car via links, so may be relevant.

Diagnosis: 

Defective harness connector

Trouble symptom: 

Subaru Select Monitor communication failure

Wiring diagram: 

CVT control system Ref. to WIRING SYSTEM (IMPREZA MODEL)>CVT CONTROL SYSTEM .

G12400250Courtesy of SUBARU OF AMERICA, INC.
CAUTION: Use the check board when measuring the TCM terminal voltage and resistance.
  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:  Replace 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 using the Subaru Select Monitor. Ref. to LAN SYSTEM (DIAGNOSTICS) (EXCEPT FOR HEV)>BASIC DIAGNOSTIC PROCEDURE .

    Is DTC of CAN communication displayed?

    Yes:  Perform the diagnosis according to the DTC. Ref. 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 transmission system can be executed normally.

    Is the [Select Function] screen displayed?

    Yes:  Check DTC of TCM. Ref. to TRANSMISSION (DIAGNOSTICS) (IMPREZA MODEL)>DIAGNOSTIC TROUBLE CODE (DTC) .

    No:  Go to  7.

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

      Connector & terminal 

      (T10) No. 8 (+) - Chassis ground (-):

      (T10) No. 24 (+) - Chassis ground (-):

      (T10) No. 34 (+) - Chassis ground (-):

      (T10) No. 40 (+) - Chassis ground (-):

      (T10) No. 41 (+) - 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. Measure the resistance of harness between TCM connector and chassis ground.

      Connector & terminal 

      (T10) No. 26 - Chassis ground:

      (T10) 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. Ref. to CONTINUOUSLY VARIABLE TRANSMISSION (TR580 IMPREZA)>TRANSMISSION CONTROL MODULE (TCM) .

scientia non olet · About LEMON Manuals