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Home >> Toyota >> 2021 >> Highlander LE, 4WD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (2GR-FKS) - Circuit Tests (2 Of 2) & Symptom Tests >> SFI System >> Starter Signal Circuit [12/2019 - 10/2022] >> Procedure

Starter Signal Circuit [12/2019 - 10/2022]: Procedure

  1. CHECK WHETHER ENGINE CAN BE CRANKED 
    1. Check if the engine can be cranked.

      Result

      Result Proceed to
      Engine cannot be cranked A
      Engine can be cranked B

    Result: 

    B 

    See step  16

    Result: 

    A 

    See step  2

  2. READ VALUE USING GTS (STARTER SW) 
    1. Check the value displayed on the GTS when the ignition switch is turned to ON and the engine is cranked.

      Powertrain > Engine > Data List 

      Tester Display
      Starter SW

      OK

      Condition GTS Display (Starter SW)
      Ignition switch ON OFF
      Cranking position ON

      Result

      Result Proceed to
      OK (w/ Stop and Start System) A
      OK (w/o Stop and Start System) B
      NG (w/ Stop and Start System) C
      NG (w/o Stop and Start System) D

    Result: 

    B 

    See step  5

    Result: 

    C 

    See step  11

    Result: 

    D 

    See step  13

    Result: 

    A 

    See step  3

  3. CHECK HARNESS AND CONNECTOR (BATTERY - STARTER ASSEMBLY) 
    1. Disconnect the cable from the negative (-) battery terminal.
    2. Disconnect the cable from the positive (+) battery terminal.
    3. Disconnect the starter assembly connector.
    4. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      Positive (+) battery terminal - C69-1 (B) Always Below 1 Ω

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  4

  4. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - ST RELAY) 
    1. Disconnect the certification ECU (smart key ECU assembly) connector.
    2. Remove the ST relay from the No. 1 engine room relay block and 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
      A19-20 (STA) - 2 (ST relay) Always Below 1 Ω

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    GO TO STOP AND START SYSTEM (STARTER SIGNAL CIRCUIT). Refer to  Starter Signal Circuit [12/2019 - 10/2022] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  5. INSPECT ST RELAY 

    Refer to INSPECTION [12/2019 - 10/2022]

    Result

    Proceed to
    OK
    NG

    Result: 

    NG 

    REPLACE ST RELAY 

    Result: 

    OK 

    See step  6

  6. INSPECT STARTER ASSEMBLY 

    Refer to INSPECTION [12/2019 - 10/2022]

    Result

    Proceed to
    OK
    NG

    Result: 

    NG 

    REPLACE STARTER ASSEMBLY. Refer to  REMOVAL [12/2019 - 10/2022] 

    Result: 

    OK 

    See step  7

  7. CHECK HARNESS AND CONNECTOR (ST RELAY - STARTER ASSEMBLY) 
    1. Remove the ST relay from the No. 1 engine room relay block and No. 1 junction block assembly.
    2. Disconnect the starter assembly connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      3 (ST relay) - C56-1 (ST) Always Below 1 Ω
      3 (ST relay) or C56-1 (ST) - Body ground and other terminals Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  8

  8. CHECK HARNESS AND CONNECTOR (ST RELAY - BODY GROUND) 
    1. Remove the ST relay from the No. 1 engine room relay block and No. 1 junction block assembly.
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      1 (ST relay) - Body ground Always Below 1 Ω

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  9

  9. CHECK HARNESS AND CONNECTOR (BATTERY - STARTER ASSEMBLY) 
    1. Disconnect the cable from the negative (-) battery terminal.
    2. Disconnect the cable from the positive (+) battery terminal.
    3. Disconnect the starter assembly connector.
    4. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      Positive (+) battery terminal - C69-1 (B) Always Below 1 Ω

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  10

  10. CHECK HARNESS AND CONNECTOR (PARK/NEUTRAL POSITION SWITCH ASSEMBLY - SMART KEY ECU ASSEMBLY - ST RELAY) 
    1. Disconnect the park/neutral position switch assembly connector.
    2. Disconnect the certification ECU (smart key ECU assembly) connector.
    3. Remove the ST relay from the No. 1 engine room relay block and No. 1 junction block assembly.
    4. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      C52-9 (L) - 2 (ST relay) Always Below 1 Ω
      A19-20 (STA) - 2 (ST relay) Always Below 1 Ω

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPAIR OR REPLACE HARNESS OR CONNECTOR (BATTERY - ST RELAY) 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  11. CHECK HARNESS AND CONNECTOR (PARK/NEUTRAL POSITION SWITCH ASSEMBLY - ECM - ST RELAY - CERTIFICATION ECU - ENGINE STOP AND START ECU) 
    1. Disconnect the park/neutral position switch assembly connector.
    2. Disconnect the ECM connector.
    3. Remove the ST relay from the No. 1 engine room relay block and No. 1 junction block assembly.
    4. Disconnect the certification ECU (smart key ECU assembly) connector.
    5. Disconnect the engine stop and start ECU connector.
    6. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      C52-9 (L) - A28-43 (STA) Always Below 1 Ω
      C52-9 (L), A28-43 (STA), 2 (ST relay), A19-20 (STA) or A34-21 (STA) - Body ground and other terminals Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  12

  12. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - PARK/NEUTRAL POSITION SWITCH ASSEMBLY - ENGINE STOP AND START ECU - ECM) 
    1. Disconnect the certification ECU (smart key ECU assembly) connector.
    2. Disconnect the park/neutral position switch assembly connector.
    3. Disconnect the engine stop and start ECU connector.
    4. Disconnect the ECM connector.
    5. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      A19-9 (STAR) - C54-106 (NSW) Always Below 1 Ω
      A19-9 (STAR), C52-4 (B), C54-106 (NSW) or A34-17 (CLL) - Body ground and other terminals Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    GO TO SMART KEY SYSTEM. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [12/2019 - 10/2021]  , or refer to  HOW TO PROCEED WITH TROUBLESHOOTING [10/2021 - 11/2023] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  13. INSPECT PARK/NEUTRAL POSITION SWITCH ASSEMBLY 

    Refer to INSPECTION [12/2019 - 10/2022]

    Result

    Proceed to
    OK
    NG

    Result: 

    NG 

    REPLACE PARK/NEUTRAL POSITION SWITCH ASSEMBLY. Refer to  REMOVAL [12/2019 - 10/2022] 

    Result: 

    OK 

    See step  14

  14. CHECK HARNESS AND CONNECTOR (PARK/NEUTRAL POSITION SWITCH ASSEMBLY - ECM - ST RELAY - CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)) 
    1. Disconnect the park/neutral position switch assembly connector.
    2. Disconnect the ECM connector.
    3. Remove the ST relay from the No. 1 engine room relay block and No. 1 junction block assembly.
    4. Disconnect the certification ECU (smart key ECU assembly) connector.
    5. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      C52-9 (L) - A28-43 (STA) Always Below 1 Ω
      C52-9 (L), A28-43 (STA), 2 (ST relay) or A19-20 (STA) - Body ground and other terminals Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  15

  15. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - PARK/NEUTRAL POSITION SWITCH ASSEMBLY - ECM) 
    1. Disconnect the certification ECU (smart key ECU assembly) connector.
    2. Disconnect the park/neutral position switch assembly connector.
    3. Disconnect the ECM connector.
    4. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      A19-9 (STAR) - C52-4 (B) Always Below 1 Ω
      A19-9 (STAR) - C54-106 (NSW) Always Below 1 Ω
      A19-9 (STAR), C52-4 (B) or C54-106 (NSW) - Body ground and other terminals Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    GO TO SMART KEY SYSTEM. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [12/2019 - 10/2021]  , or refer to  HOW TO PROCEED WITH TROUBLESHOOTING [10/2021 - 11/2023] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  16. READ VALUE USING GTS (STARTER SW) 
    1. Check the value displayed on the GTS when the ignition switch is turned to ON and the engine is cranked.

      Powertrain > Engine > Data List 

      Tester Display
      Starter SW

      OK

      Condition GTS Display (Starter SW)
      Ignition switch ON OFF
      Cranking position ON

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to  PROBLEM SYMPTOMS TABLE [12/2019 - 10/2022] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR (ST RELAY - ECM) 

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