LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Lexus >> 2016 >> GS 450h Base >> Repair and Diagnosis >> Electrical >> Starter >> Smart Access System With Push-Button Start (For Start Function) (Diagnostic Codes & Symptom Tests) >> SMART ACCESS SYSTEM WITH PUSH-BUTTON START (for Start Function) >> Symptom Tests >> Power Source Mode does not Change to ON (IG) [10/2015 - ] >> Procedure
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Power Source Mode does not Change to ON (IG) [10/2015 - ]: Procedure

  1. CHECK HARNESS AND CONNECTOR (POWER MANAGEMENT CONTROL ECU - NO. 1 INTEGRATION RELAY) 
    1. Disconnect the A36 connectors from the power management control ECU.
    2. Disconnect the 1E and 1F connectors from the No. 1 integration relay.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      A36-2 (IG2D) - 1E-2 Always Below 1 Ω
      1F-1 - Body ground
      A36-2 (IG2D) - 1E-2 - Body ground 10 kΩ or higher

    Result:  NG

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result:  OK

    OK 

    See step  2

  2. INSPECT NO. 1 INTEGRATION RELAY (IG2 RELAY) 
    1. Remove the No. 1 integration relay.
      GTY529773Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      1F-6 - 1D-1 Battery voltage not applied to terminals 1E-2 and 1F-1 10 kΩ or higher
      Battery voltage applied to terminals 1E-2 and 1F-1 Below 1 Ω
      TEXT IN ILLUSTRATION

      *a Component without harness connected
      (No. 1 Integration Relay)

    Result:  NG

    NG 

    REPLACE NO. 1 INTEGRATION RELAY 

    Result:  OK

    OK 

    See step  3

  3. CHECK HARNESS AND CONNECTOR (POWER MANAGEMENT CONTROL ECU - COWL SIDE JUNCTION BLOCK RH) 
    1. Disconnect the N92 connector from the power management control ECU.
    2. Disconnect the 4A connector from the connector from the cowl side junction block RH.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      N92-2 (IG1D) - 4A-25 Always Below 1 Ω
      4A-4 - Body ground
      N92-2 (IG1D) and 4A-25 - Body ground 10 kΩ or higher

    Result:  NG

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result:  OK

    OK 

    See step  4

  4. CHECK HARNESS AND CONNECTOR (COWL SIDE JUNCTION BLOCK RH - COWL SIDE JUNCTION BLOCK LH) 
    1. Disconnect the 4A connector from the cowl side junction block RH.
    2. Disconnect the 5A and 5B connectors from the cowl side junction block LH.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      4A-40 - 5A-35 Always Below 1 Ω
      5B-1 - Body ground
      4A-40 and 5A-35 - Body ground 10 kΩ or higher

    Result:  NG

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result:  OK

    OK 

    See step  5

  5. CHECK HARNESS AND CONNECTOR (COWL SIDE JUNCTION BLOCK LH - NO. 1 JUNCTION BLOCK ASSEMBLY) 
    1. Disconnect the 5C connector from the cowl side junction block LH.
    2. Disconnect the 6B and 6A connectors from the No. 1 junction block assembly.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      5C-13 - 6B-8 Always Below 1 Ω
      6A-9 - Body ground
      5C-13 and 6B-8 - Body ground 10 kΩ or higher

    Result:  NG

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result:  OK

    OK 

    See step  6

  6. INSPECT COWL SIDE JUNCTION BLOCK RH (RH-IG1 RLY1, RH-IG1 RLY2 RELAY) 
    1. Remove the cowl side junction block RH.
    2. Measure the resistance according to the value(s) in the table below.
      GTY523274Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

      *a Component without harness connected
      (Cowl Side Junction Block RH)      		 - -

      Standard Resistance

      Tester Connection Condition Specified Condition
      4E-1 - 4D-4 Auxiliary battery voltage not applied to terminals 4A-25 and 4A-4 10 kΩ or higher
      Auxiliary battery voltage applied to terminals 4A-25 and 4A-4 Below 1 Ω
      4E-1 - 4A-6 Auxiliary battery voltage not applied to terminals 4A-25 and 4A-4 10 kΩ or higher
      Auxiliary battery voltage applied to terminals 4A-25 and 4A-4 Below 1 Ω

    Result:  NG

    NG 

    REPLACE COWL SIDE JUNCTION BLOCK RH 

    Result:  OK

    OK 

    See step  7

  7. INSPECT COWL SIDE JUNCTION BLOCK LH (LH-IG1 RLY1, LH-IG1 RLY2 RELAY) 
    1. Remove the cowl side junction block LH (Refer to REMOVAL [09/2014 - ] ).
    2. Measure the resistance according to the value(s) in the table below.
      GTY525926Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

      *a Component without harness connected
      (Cowl Side Junction Block LH)      		 - -

      Standard Resistance

      Tester Connection Condition Specified Condition
      5E-1 - 5B-7 Auxiliary battery voltage not applied to terminals 5A-35 and 5B-1 10 kΩ or higher
      Auxiliary battery voltage applied to terminals 5A-35 and 5B-1 Below 1 Ω
      5E-1 - 5D-7 Auxiliary battery voltage not applied to terminals 5A-35 and 5B-1 10 kΩ or higher
      Auxiliary battery voltage applied to terminals 5A-35 and 5B-1 Below 1 Ω

    Result:  NG

    NG 

    REPLACE MAIN BODY ECU (COWL SIDE JUNCTION BLOCK LH) 

    (Refer to REMOVAL [09/2014 - ] )

    Result:  OK

    OK 

    See step  8

  8. INSPECT NO. 1 JUNCTION BLOCK ASSEMBLY (RR-IG1 RLY1, RR-IG1 RLY2 RELAY) 
    1. Remove the No. 1 junction block assembly.
    2. Measure the resistance according to the value(s) in the table below.
      GTY535251Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

      *a Component without harness connected
      (No. 1 Junction Block Assembly)      		 - -

      Standard Resistance

      Tester Connection Condition Specified Condition
      6D-1 - 6B-14 Auxiliary battery voltage not applied to terminals 6B-8 and 6A-9 10 kΩ or higher
      Auxiliary battery voltage applied to terminals 6B-8 and 6A-9 Below 1 Ω
      6D-1 - 6A-8 Auxiliary battery voltage not applied to terminals 6B-14 and 6A-9 10 kΩ or higher
      Auxiliary battery voltage applied to terminals 6B-14 and 6A-9 Below 1 Ω

    Result:  NG

    NG 

    REPLACE NO. 1 JUNCTION BLOCK ASSEMBLY 

    Result:  OK

    OK 

    See step  9

  9. CHECK POWER MANAGEMENT CONTROL ECU 
    1. Measure the voltage according to the value(s) in the table below.
      GTY538056Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      TEXT IN ILLUSTRATION

      *a Component with harness connected
      (Power Management Control ECU)

      Standard Voltage

      Tester Connection Condition Specified Condition
      A36-2 (IG2D) - Body ground Power switch on (ACC) → Power switch on (IG) 1 V or less → 9 V or higher
      N92-2 (IG1D) - Body ground Power switch on (ACC) → Power switch on (IG) 1 V or less → 9 V or higher

    Result:  OK

    OK 

    CHECK RELAY CONTACT SIDE CIRCUIT 

    Result:  NG

    NG 

    REPLACE POWER MANAGEMENT CONTROL ECU 

    (Refer to REMOVAL [09/2014 - ] )

scientia non olet · About LEMON Manuals