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Home >> Lexus >> 2025 >> NX 250 FWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 147 (Smart Access System (For Start) - Symptom Tests (2 Of 2)) >> SMART ACCESS SYSTEM WITH PUSH-BUTTON START (for Start Function, HEV Model) >> Security Indicator Light Does not Blink [11/2021 - ] >> Procedure

Security Indicator Light Does not Blink [11/2021 - ]: Procedure

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  1. CHECK FOR DTC 
    1. Check for DTCs.

      Body Electrical > Smart Access > Trouble Codes 

      Powertrain > Hybrid Control > Trouble Codes 

      OK

      DTCs are not output.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    GO TO DIAGNOSTIC TROUBLE CODE CHART. Refer to  DIAGNOSTIC TROUBLE CODE CHART [11/2021 - 03/2023]  , or refer to  DIAGNOSTIC TROUBLE CODE CHART [03/2023 - ] 

    Result: 

    OK 

    See step  2

  2. PERFORM ACTIVE TEST USING GTS (IMMOBILIZER INDICATOR) 
    1. Perform the Active Test according to the display on the GTS.

      Body Electrical > Smart Access > Active Test 

      Tester Display Measurement Item Control Range Diagnostic Note
      Immobilizer Indicator Security indicator light OFF/ON -

      Body Electrical > Smart Access > Active Test 

      Tester Display
      Immobilizer Indicator

      OK

      The security indicator light (theft warning indicator light assembly) operates normally.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  4

    Result: 

    OK 

    See step  3

  3. CHECK SECURITY INDICATOR LIGHT (THEFT WARNING INDICATOR LIGHT ASSEMBLY) OPERATION 
    1. When the immobilizer is set, check that the security indicator light (theft warning indicator light assembly) blinks.*1

      OK

      The security indicator light (theft warning indicator light assembly) blinks normally.

    2. When the theft deterrent system is in the arming preparation state, check that the security indicator light (theft warning indicator light assembly) illuminates.*2

      OK

      The security indicator light (theft warning indicator light assembly) illuminates normally.

      Result

      Result Proceed to
      *1 is NG (*2 is OK) A
      *2 is NG (*1 is OK) B

    Result: 

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY). Refer to  REMOVAL [11/2021 - ] 

    Result: 

    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU). Refer to  REMOVAL [11/2021 - ] 

  4. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - SECURITY INDICATOR LIGHT (THEFT WARNING INDICATOR LIGHT ASSEMBLY)) 
    1. Disconnect the D58 certification ECU (smart key ECU assembly) connector.
    2. Disconnect the D142 security indicator light (theft warning indicator light assembly) connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      D58-25 (IND) - D142-1 (LP) Always Below 1 Ω
      D58-25 (IND) or D142-1 (LP) - Other terminals and body ground Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  5

  5. CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) 
    1. Connect the D58 certification ECU (smart key ECU assembly) connector.
      GTY1081004Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Component with harness connected
      (Certification ECU (Smart Key ECU Assembly))
    2. Connect the D142 security indicator light (theft warning indicator light assembly) connector.
    3. Using an oscilloscope, check the waveform.

      Measurement Condition

      Tester Connection Condition Specified Condition
      D58-25 (IND) - Body ground Ignition switch off → ON Pulse generation → Below 2 V

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE SECURITY INDICATOR LIGHT (THEFT WARNING INDICATOR LIGHT ASSEMBLY) 

    Result: 

    NG 

    REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY). Refer to  REMOVAL [11/2021 - ]