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Home >> Toyota >> 2021 >> Sequoia TRD Pro >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Engine Control System (3UR-FE) - Circuit Tests (2 Of 2) >> SFI System >> ECM Power Source Circuit [08/2017 - 08/2019] >> Procedure
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ECM Power Source Circuit [08/2017 - 08/2019]: Procedure

  1. INSPECT FUSES (AM2, IG2 MAIN, EFI NO. 1, IGN) 
    1. Remove the AM2 fuse, IG2 MAIN fuse, EFI NO. 1 fuse and IGN fuse from the engine room relay block.
    2. Measure the resistance according to the value(s) in the table below.

      Standard resistance

      Tester Connection Condition Specified Condition
      AM2 fuse Always Below 1 Ω
      IG2 MAIN fuse Always Below 1 Ω
      EFI NO. 1 fuse Always Below 1 Ω
      IGN fuse Always Below 1 Ω

    Result: 

    NG 

    CHECK FOR SHORT IN ALL HARNESSES AND CONNECTORS CONNECTED TO FUSE AND REPLACE FUSE 

    Result: 

    OK 

    See step  2

  2. INSPECT RELAY (IG2, EFI MAIN) 
    GTY744590Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Remove the integration relay from the engine room relay block.
    2. Measure the resistance according to the value(s) in the table below.

      Standard resistance

      Tester Connection Condition Specified Condition
      2C-1 - 2B-8 When no battery voltage is applied to terminals 1B-6 and 1B-7 10 kΩ or higher
      2C-1 - 2B-8 When battery voltage is applied to terminals 1B-6 and 1B-7 Below 1 Ω
      2C-1 - 2B-4 When no battery voltage is applied to terminals 1B-2 and 1B-3 10 kΩ or higher
      2C-1 - 2B-4 When battery voltage is applied to terminals 1B-2 and 1B-3 Below 1 Ω

    Result: 

    NG 

    REPLACE RELAY 

    Result: 

    OK 

    See step  3

  3. CHECK HARNESS AND CONNECTOR (ECM - BODY GROUND) 
    1. Disconnect the D56 ECM connector.
    2. Measure the resistance according to the value(s) in the table below.

      Standard resistance

      Tester Connection Condition Specified Condition
      D56-81 (E1) - Body ground Always Below 1 Ω

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  4

  4. INSPECT ECM (IGSW VOLTAGE) 
    GTY758406Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Disconnect the A27 and D56 ECM connectors.
    2. Turn the ignition switch to ON.
    3. Measure the voltage according to the value(s) in the table below.

      Standard voltage

      Tester Connection Switch Condition Specified Condition
      A27-4 (IGSW) - D56-81 (E1) Ignition switch ON 11 to 14 V

    Result: 

    OK 

    REPLACE ECM 

    (Refer to REMOVAL [08/2015 - ] )

    Result: 

    NG 

    See step  5

  5. CHECK HARNESS AND CONNECTOR (RELAY BLOCK - ECM, IGNITION SWITCH, BATTERY AND BODY GROUND) 
    1. Disconnect the A27 ECM connector.
    2. Disconnect the H10 ignition switch connector.
    3. Disconnect the cable from the battery positive (+) terminal.
    4. Remove the AM2 fuse and integration relay.
    5. Measure the resistance according to the value(s) in the table below.

      Standard resistance

      Tester Connection Condition Specified Condition
      A27-4 (IGSW) - 2B-8 Always Below 1 Ω
      2B-7 - Body ground Always Below 1 Ω
      Positive (+) battery cable - 2C-1 Always Below 1 Ω
      Positive (+) battery cable - AM2 fuse terminal 1 Always Below 1 Ω
      H10-5 (AM2) - AM2 fuse terminal 2 Always Below 1 Ω
      H10-6 (IG2) - 2B-6 Always Below 1 Ω
      A27-4 (IGSW) or 2B-8 - Body ground Always 10 kΩ or higher
      Positive (+) battery cable or AM2 fuse terminal 1 - Body ground Always 10 kΩ or higher
      Positive (+) battery cable or 2C-1 - Body ground Always 10 kΩ or higher
      H10-5 (AM2) or AM2 fuse terminal 2 - Body ground Always 10 kΩ or higher
      H10-6 (IG2) or 2B-6 - Body ground Always 10 kΩ or higher

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  6

  6. INSPECT IGNITION SWITCH 
    1. Inspect the ignition switch (Refer to INSPECTION [08/2015 - 08/2019] ).

    Result: 

    NG 

    REPLACE IGNITION SWITCH 

    (Refer to REMOVAL [08/2015 - 08/2019] )

    Result: 

    OK 

    See step  7

  7. CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY - ECM, BATTERY AND BODY GROUND) 
    1. Disconnect the A27 ECM connector.
    2. Disconnect the cable from the battery positive terminal.
    3. Remove the integration relay from the engine room relay block.
    4. Disconnect the integration relay connector.
    5. Measure the resistance according to the value(s) in the table below.

      Standard resistance

      Tester Connection Condition Specified Condition
      A27-2 (+B) - 2B-4 Always Below 1 Ω
      A27-3 (+B2) - 2B-4 Always Below 1 Ω
      A27-6 (MREL) - 2B-2 Always Below 1 Ω
      2C-1 - Positive (+) battery cable Always Below 1 Ω
      2B-3 - Body ground Always Below 1 Ω
      A27-2 (+B) or 2B-4 - Body ground Always 10 kΩ or higher
      A27-3 (+B2) or 2B-4 - Body ground Always 10 kΩ or higher
      A27-6 (MREL) or 2B-2 - Body ground Always 10 kΩ or higher
      2C-1 or Positive (+) battery cable - Body ground Always 10 kΩ or higher

    Result: 

    OK 

    REPAIR OR REPLACE ENGINE ROOM RELAY BLOCK 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

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