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Basic Diagnostic Procedure: Procedure

CAUTION:
  • Subaru Select Monitor is required for reading DTC, performing diagnosis, reading current data, customizing and active test (compulsory drive).
  • Remove foreign matter (dust, water, oil, etc.) from each control module connector during removal and installation.
  • Registration of immobilizer may be needed after the replacement of control modules, etc. For detailed procedure, refer to the "REGISTRATION MANUAL FOR IMMOBILIZER" provided as a separate volume.
NOTE:
  • To check harness for open or short circuits, shake the suspected trouble spot or connector.
  • Perform the diagnosis, and when the control module is replaced as a result of judgment that malfunction is the control module, re-check that the control module was actually malfunctioning. Replace to a new control module, and confirm that the malfunction is eliminated. Then, install the previously removed control module again and check that the malfunction reproduces again.
  • Check List for Interview Refer to LAN SYSTEM (DIAGNOSTICS)>CHECK LIST FOR INTERVIEW .
  1. CHECK PRE-INSPECTION. 

    Ask the customer when and how the trouble occurred using the Check List for Interview. Refer to LAN SYSTEM (DIAGNOSTICS)>CHECK LIST FOR INTERVIEW .

    Did you interview the customer?

    Yes:  Go to  2.

    No:  Interview the customer.

  2. BASIC INSPECTION (CAN DIAGNOSTIC IS NOT USED). 

    Check the power supply circuit of the module which might affect CAN communication problem. Refer to LAN SYSTEM (DIAGNOSTICS)>GENERAL DESCRIPTION>INSPECTION>INSPECTION WITHOUT USING CAN DIAGNOSTIC .

    Is the power supply circuit of each module that is performing CAN communication normal?

    Yes:  Go to  3.

    No:  Repair or replace the faulty portion.

  3. BASIC INSPECTION (CAN DIAGNOSTIC IS USED). 

    Check the registration status of the body integrated unit which might affect CAN communication problem. Refer to LAN SYSTEM (DIAGNOSTICS)>GENERAL DESCRIPTION>INSPECTION>INSPECTION USING CAN DIAGNOSTIC .

    Does the registration status of the body integrated unit match the vehicle specification? (When the Subaru Select Monitor and the body integrated unit cannot communicate, and the registration status cannot be checked, Go to  5.)

    Yes:  Go to  4.

    No:  Match the registration status of the body integrated unit with the vehicle specification.

  4. CHECK COMMUNICATION FOR INITIALIZING. 

    Communicate with the all systems by connecting the Subaru Select Monitor.

    Is the communication for initializing finished for all modules?

    Yes:  Go to  5.

    No:  Check the error of communication for initializing. Refer to LAN SYSTEM (DIAGNOSTICS)>SUBARU SELECT MONITOR>COMMUNICATION FOR INITIALIZING IMPOSSIBLE .

  5. CHECK DTC. 
    1. Start the engine and read all DTCs.
      NOTE: When the engine does not start, perform the diagnosis for the engine start malfunction. Refer to ENGINE (DIAGNOSTICS) (W/O STI)>DIAGNOSTICS FOR ENGINE STARTING FAILURE . Refer to ENGINE (DIAGNOSTICS) (STI)>DIAGNOSTICS FOR ENGINE STARTING FAILURE .
    2. Record all DTCs (current malfunction and past malfunction), time stamp and freeze frame data.
      NOTE: For time stamp, refer to "TIME STAMP" of General Description. Refer to LAN SYSTEM (DIAGNOSTICS)>GENERAL DESCRIPTION>CAUTION>TIME STAMP .

    Is DTC U**** displayed on Subaru Select Monitor?

    Yes:  Go to  6.

    No:  Using the diagnostics with phenomenon, perform inspection. Refer to LAN SYSTEM (DIAGNOSTICS)>DIAGNOSTICS WITH PHENOMENON .

  6. CHECK USING THE DTC CHECK SHEET. 

    Perform the inspection using the DTC check sheet. Refer to LAN SYSTEM (DIAGNOSTICS)>LIST OF DIAGNOSTIC TROUBLE CODE (DTC)>LIST>CHECK USING THE DTC CHECK SHEET .

    Is CAN communication line faulty?

    Yes:  Repair or replace the faulty portion of the harness. And then, Go to  7.

    No:  Perform the diagnosis for the displayed DTCs. And then, Go to  7.

  7. PERFORM DIAGNOSIS. 
    1. Perform the Clear Memory Mode. Refer to LAN SYSTEM (DIAGNOSTICS)>CLEAR MEMORY MODE>OPERATION .
    2. Read the DTC. Refer to LAN SYSTEM (DIAGNOSTICS)>READ DIAGNOSTIC TROUBLE CODE (DTC)>OPERATION .

    Are any DTCs displayed?

    Yes:  Repeat the Basic Diagnostic Procedure from the beginning until DTC is not shown.

    No:  Finish the diagnosis.

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