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How To Proceed With Troubleshooting

WARNING: This page is about a different car, the 2007 Lexus SC 430. However, it is still accessible from the selected car via links, so may be relevant.

HINT:

  1. VEHICLE BROUGHT TO WORKSHOP 
  2. CUSTOMER PROBLEM ANALYSIS CHECK AND SYMPTOM CHECK 
  3. INSPECT BATTERY VOLTAGE 

    Standard voltage: 

    11 to 14 V 

    If the voltage is below 11V, recharge or replace the battery before proceeding.

  4. INSPECT COMMUNICATION FUNCTION OF LARGE-SCALE MULTIPLEX COMMUNICATION SYSTEM (BEAN) 
    1. Using the intelligent tester to check if the Multiplex Communication System (MPX) is functioning normally.

      Result 

      RESULT CHART

      Result Proceed to
      MPX DTC is not output A
      MPX DTC is output B

    B:  GO to MULTIPLEX COMMUNICATION SYSTEM

    A: Go to next step 

  5. BASIC INSPECTION 
    1. Turn the ignition switch to ACC.
    2. Check whether or not the multi-display turns on.

      Result 

      RESULT CHART

      Result Proceed to
      Display turns on A
      Display does not turn on B

    B: Go to step  7

    A: Go to next step 

  6. CHECK FOR DTC 
    1. Check for DTCs and note any codes that are output.
    2. Delete the DTC.
    3. Recheck for DTCs. Based on the DTC output in (a), try to force output of the navigation system DTC by simulating the operation indicated by the DTC.

      HINT:

      • If the system cannot enter the diagnosis mode, inspect each AVC-LAN communication signal and repair or replace problem parts.
      • Even if the malfunction symptom is not confirmed, check the DTCs. This is because the system stores past DTCs.
      • Refer to the detailed description on the diagnostic screen as necessary (see DTC CHECK / CLEAR  ).
      • Check the clear the past diagnostic trouble code. Check the diagnostic trouble code and inspect the area the code indicates.

        Result 

        RESULT CHART

        Result Proceed to
        DTC does not reoccur A
        DTC reoccurs B

    B: Go to step  8

    A: Go to next step 

  7. PROBLEM SYMPTOMS TABLE 

    Result 

    RESULT CHART

    Result Proceed to
    Fault is not listed on problem symptoms table A
    Fault is listed on problem symptoms table B

    B: Go to step  9

    A: Go to next step 

  8. OVERALL ANALYSIS AND TROUBLESHOOTING 
    1. (see TERMINALS OF ECU  )
  9. ADJUST, REPAIR OR REPLACE 

    END