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Home >> Lexus >> 2008 >> GS 350 AWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - System And Circuit Testing, On-Vehicle Inspection, Removal, Inspection & Installation >> Cranking Holding Function Circuit >> Inspection Procedure
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Inspection Procedure

  1. CHECK OPERATION OF CRANKING 
    1. When starting the engine, check whether the starter motor starts.

    OK : CHECK FOR INTERMITTENT PROBLEMS 

    NG : Go to next step 

  2. READ VALUE USING TECHSTREAM (STA SIGNAL) 
    1. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG) and turn the Techstream on.
    3. Select the following menu items: Powertrain/Engine and ECT/Data List/Starter Signal.
    4. Check the result when the engine switch is turned on (IG) and the engine is started.

      Standard 

      ENGINE SWITCH POSITION

      STARTER SIG Engine Switch Position
      OFF on (IG)
      ON ENGINE START

    OK :  Go to step  6

    NG : Go to next step 

  3. INSPECT ECM (STAR AND STSW VOLTAGE) 
    1. Measure the voltage according to the value(s) in the table below while cranking the engine.

      Standard voltage 

      STANDARD VOLTAGE SPECIFICATION

      Tester Connection Specified Condition
      E7-4 (STAR) - E7-7 (E1) 11 to 14 V
      A6-19 (STSW) - E7-7 (E1) 11 to 14 V
      Fig 1: Identifying E7 And A6 ECM Connector
      G05285310Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Result 

      RESULT REFERENCE

      Terminal STAR Terminal STSW Proceed to
      9 to 14V 9 to 14 V A
      0 V 9 to 14 V B
      0 V 0 V C

    B : REPLACE ECM 

    C :  Go to step  10

    A : Go to next step 

  4. INSPECT ST CUT RELAY 
    1. Remove the ST CUT relay from the engine room No. 2 relay block.
    2. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      STANDARD RESISTANCE SPECIFICATION

      Tester Connection Specified Condition
      3-5 10 kΩ or higher
      3-5 Below 1 Ω (when battery voltage applied to terminals 1 and 2)

    NG : REPLACE ST CUT RELAY 

    Fig 2: Inspecting ST CUT Relay
    G04942983Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK : Go to next step 

  5. INSPECT PARK/NEUTRAL POSITION SWITCH ASSEMBLY 
    1. Disconnect the E77 park/neutral position (PNP) switch connector.
    2. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      STANDARD RESISTANCE SPECIFICATION

      Tester Connection Shift Position Specified Condition
      4-5 P Below 1 Ω
      4-5 N Below 1 Ω
      Fig 3: Identifying E77 Park/Neutral Position (PNP) Switch Connector
      G05285312Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG : REPLACE PARK/NEUTRAL POSITION SWITCH ASSEMBLY 

    OK : CHECK AND REPAIR HARNESS AND CONNECTOR (PARK/NEUTRAL POSITION SWITCH - ECM, ECM - ST CUT RELAY, ST) 

  6. INSPECT STARTER RELAY 
    1. Remove the STARTER relay from the engine room No. 1 relay block.
    2. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      STANDARD RESISTANCE SPECIFICATION

      Tester Connection Specified Condition
      3-5 10 kΩ or higher
      3-5 Below 1 Ω (when battery voltage applied to terminals 1 and 2)

    NG : REPLACE STARTER RELAY 

    Fig 4: Inspecting STARTER Relay
    G04942976Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK : Go to next step 

  7. CHECK HARNESS AND CONNECTOR (PARK/NEUTRAL POSITION SWITCH - STARTER RELAY) 
    1. Check the harness and the connectors between the park/neutral position switch and the starter relay.
      1. Disconnect the E77 PNP switch connector.
      2. Remove the starter relay from the engine room No. 1 relay block.
      3. Measure the resistance according to the value(s) in the table below.

        Standard resistance (Check for open) 

        STANDARD RESISTANCE SPECIFICATION

        Tester Connection Specified Condition
        Park/Neutral position switch (E77-5) - STARTER relay (1) Below 1 Ω

        Standard resistance (Check for short) 

        STANDARD RESISTANCE SPECIFICATION

        Tester Connection Specified Condition
        Park/Neutral position switch (E77-5) or STARTER relay (1) - Body ground 10 kΩ or higher
        Fig 5: Identifying STARTER Relay And E77 PNP Switch Connector
        G05285314Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Check the harness and the connector between the starter relay and the body ground.
      1. Remove the starter relay from the engine room No. 1 relay block.
      2. Measure the resistance according to the value(s) in the table below.

        Standard resistance (Check for open) 

        STANDARD RESISTANCE SPECIFICATION

        Tester Connection Specified Condition
        STARTER relay (2) - Body ground Below 1 Ω

    NG : REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK : Go to next step 

  8. INSPECT ENGINE ROOM RELAY BLOCK (STARTER RELAY VOLTAGE) 
    1. Remove the starter relay from the engine room No. 1 relay block.
    2. Measure the voltage according to the value(s) in the table below.

      Standard voltage 

      STANDARD VOLTAGE SPECIFICATION

      Tester Connection Specified Condition
      STARTER relay (S) - Body ground 9 to 14 V

    NG : REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Fig 6: Identifying Starter Relay From Engine Room No. 1 Relay Block
    G05285315Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK : Go to next step 

  9. INSPECT STARTER ASSEMBLY 

    NG : REPAIR OR REPLACE STARTER ASSEMBLY 

    OK : REPAIR OR REPLACE HARNESS OR CONNECTOR (STARTER RELAY - STARTER, STARTER - BATTERY) 

  10. CHECK HARNESS AND CONNECTOR (POWER SOURCE CONTROL ECU - ECM) 
    1. Check the harness and the connectors between the power source control ECU and ECM.
      1. Disconnect the power source control ECU connector.
      2. Disconnect the A6 ECM connector.
      3. Measure the resistance according to the value(s) in the table below.

        Standard resistance (Check for open) 

        STANDARD RESISTANCE SPECIFICATION

        Tester Connection Specified Condition
        K73-39 (STSW) - A6-19 (STSW) Below 1 Ω

        Standard resistance (Check for short) 

        STANDARD RESISTANCE SPECIFICATION

        Tester Connection Specified Condition
        K73-39 (STSW) or A6-19 (STSW) - Body ground 10 kΩ or higher

    NG : REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Fig 7: Identifying K73 Power Source Control ECU And A6 ECM Connectors
    G05803514Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK :  GO TO PUSH BUTTON START SYSTEM

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