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Home >> Lexus >> 2008 >> IS 250 RWD, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (4GR-FSE) - System And Component Testing, On-Vehicle Inspection, Removal, Inspection & Installation >> Cranking Holding Function Circuit >> Inspection Procedure
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Inspection Procedure

  1. CHECK 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 OF TECHSTREAM (STA SIGNAL) 
    1. Connect Techstream to the DLC3.
    2. Turn the engine switch on (IG) and turn the tester on.
    3. Enter the following menus: 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 CHART

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

    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 

    VOLTAGE SPECIFICATION CHART

    Tester Connection Specified Condition
    STAR (E4-4) - E1 (E4-7) 9 to 14 V
    STSW (A5-19) - E1 (E4-7) 9 to 14 V

    Result 

    RESULT CHART

    Terminal STAR Terminal STSW Proceed to
    9 to 14 V 9 to 14 V A
    0V 9 to 14 V B
    0V 0V C
    Fig 1: Identifying ECM Connector A5 And E4
    G05823283Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    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 R/B No. 2.
    2. Measure the resistance according to the value (s) in the table below.

    Standard resistance 

    RESISTANCE SPECIFICATION CHART

    Tester Connection Specified Condition
    3-5 10 kΩ or higher
    3-5 Below 1 Ω (when battery voltage applied to terminals 1 and 2)
    Fig 2: Inspecting ST CUT Relay Terminal
    G04942983Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPLACE ST CUT RELAY 

    OK: Go to Next Step 

  5. INSPECT PARK/NEUTRAL POSITION SWITCH ASSEMBLY (A/T) OR CLUTCH PEDAL SWITCH ASSEMBLY (M/T) 
    1. Disconnect the park/neutral position (PNP) switch (A/T) or clutch pedal switch (M/T) connector.
    2. Measure the resistance according to the value (s) in the table below.

    Standard resistance (A/T) 

    RESISTANCE SPECIFICATION CHART

    Shift Position Tester Connection Specified Condition
    P 4 - 5 Below 1 Ω
    N 4 - 5 Below 1 Ω

    Standard resistance (M/T) 

    RESISTANCE SPECIFICATION CHART

    Clutch Pedal Operation Tester Connection Specified Condition
    Depressed 1 - 2 Below 1 Ω
    Fig 3: Identifying Park/Neutral Position Switch (A/T) Or Clutch Pedal Switch (M/T) Connector
    G05823285Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPLACE PARK/NEUTRAL POSITION SWITCH (A/T) OR CLUTCH PEDAL SWITCH (M/T) 

    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 R/B No. 1.
    2. Measure the resistance according to the value (s) in the table below.

    Standard resistance 

    RESISTANCE SPECIFICATION CHART

    Tester Connection Specified Condition
    3-5 10 kΩ or higher
    3-5 Below 1 Ω (when battery voltage applied to terminals 1 and 2)
    Fig 4: Inspecting Starter Relay
    G04942976Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPLACE STARTER RELAY 

    OK: Go to Next Step 

  7. CHECK HARNESS AND CONNECTOR (PNP SWITCH (A/T) OR CLUTCH PEDAL SWITCH (M/T) - ST RELAY) 
    1. Check the harness and the connectors between the park/neutral position switch and the starter relay.
      1. Disconnect the E45*1, A24*2 switch connector.

        *1:A/T

        *2:M/T

      2. Remove the starter relay from the engine room R/B No. 1.
      3. Measure the resistance according to the value (s) in the table below.

      Standard resistance (A/T) (Check for open) 

      RESISTANCE SPECIFICATION CHART

      Tester Connection Specified Condition
      Park/Neutral position switch (E45-5) - STARTER relay (1) Below 1 Ω

      Standard resistance (M/T) (Check for open) 

      RESISTANCE SPECIFICATION CHART

      Tester Connection Specified Condition
      Clutch pedal switch (A24-2) - STARTER relay (1) Below 1 Ω

      Standard resistance (A/T) (Check for short) 

      RESISTANCE SPECIFICATION CHART

      Tester Connection Specified Condition
      Park/Neutral position switch (E45-5) or STARTER relay (1) - Body ground 10 kΩ or higher

      Standard resistance (M/T) (Check for short) 

      RESISTANCE SPECIFICATION CHART

      Tester Connection Specified Condition
      Clutch pedal switch (A24-2) or STARTER relay (1) - Body ground 10 kΩ or higher
      Fig 5: Identifying PNP Switch (A/T) Connector E45 And Clutch Pedal Switch (M/T) Connector A24
      G05823287Courtesy 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 R/B No. 1.
      2. Measure the resistance according to the value (s) in the table below.

      Standard resistance (Check for open) 

      RESISTANCE SPECIFICATION CHART

      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 R/B No. 1.
    2. Measure the voltage according to the value (s) in the table below.

    Standard voltage 

    VOLTAGE SPECIFICATION CHART

    Tester Connection Specified Condition
    STARTER relay (5) - Body ground 9 to 14 V
    Fig 6: Identifying Starter Relay From Engine Room R/B No. 1
    G05823288Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    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 A5 ECM connector.
      3. Measure the resistance according to the value (s) in the table below.

      Standard resistance (Check for open) 

      RESISTANCE SPECIFICATION CHART

      Tester Connection Specified Condition
      J55-39 (STSW) - A5-19 (STSW) Below 1 Ω

      Standard resistance (Check for short) 

      RESISTANCE SPECIFICATION CHART

      Tester Connection Specified Condition
      J55-39 (STSW) or A5-19 (STSW) - Body ground 10 kΩ or higher
      Fig 7: Identifying A5 ECM Connector And Power Source Control ECU Connector J55
      G05316187Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

      OK:  GO TO SMART ACCESS SYSTEM WITH PUSH-BUTTON START

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