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Home >> Toyota >> 2007 >> Tundra Base, 5.7 V, RWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (3UR-FE) - System Testing, Removal & Installation >> ECM Power Source Circuit >> Inspection Procedure
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Inspection 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 

      FUSES (AM2, IG2 MAIN, EFI NO. 1, IGN)

      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
      Fig 1: Identifying Engine Room Relay Block Connector Terminal
      G05149948Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

    OK: Go to next step 

  2. INSPECT RELAY (IG2, EFI) 
    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 

      RELAY (IG2, EFI)

      Tester Connection Condition Specified Condition
      1C-1 - 1B-8 When no battery voltage is applied to terminals 1B-6 and 1B-7 10 kΩ or higher
      1C-1 - 1B-8 When battery voltage is applied to terminals 1B-6and1B-7 Below 1 Ω
      1C-1 - 1B-4 When no battery voltage is applied to terminals 1B-2 and 1B-3 10 kΩ or higher
      1C-1 - 1B-J When battery voltage is applied to terminals 1B-2 and 1B-3 Below 1 Ω
      Fig 2: Identifying Integration Relay Connector Terminals
      G05149697Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPLACE RELAY  (see ON-VEHICLE INSPECTION  )

    OK: Go to next step 

  3. CHECK HARNESS AND CONNECTOR (ECM - BODY GROUND) 
    1. Disconnect the D74 ECM connector.
    2. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      ECM - BODY GROUND

      Tester Connection Condition Specified Condition
      D74-81 (E1) - Body ground Always Below 1 Ω
      Fig 3: Identifying D74 ECM Connector Terminal
      G05149950Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  4. INSPECT ECM (IGSW VOLTAGE) 
    1. Disconnect the A24 and D74 ECM connectors.
    2. Turn the ignition switch ON.
    3. Measure the voltage according to the value(s) in the table below.

      Standard voltage 

      ECM (IGSW VOLTAGE)

      Tester Connection Switch Condition Specified Condition
      A24-28 (IGSW) - D74-81 (E1) Ignition switch ON 11 to 14 V
      Fig 4: Identifying A24 And D74 ECM Connector Terminal
      G05149951Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: Go to step 5 

    OK: REPLACE ECM  (see REMOVAL  )

  5. CHECK HARNESS AND CONNECTOR (RELAY BLOCK - ECM, IGNITION SWITCH, BATTERY AND BODY GROUND) 
    1. Disconnect the A24 ECM connector.
    2. Disconnect the J9 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 

      RELAY BLOCK - ECM, IGNITION SWITCH, BATTERY AND BODY GROUND

      Tester Connection Condition Specified Condition
      A24-28(IGSW) - 1B-8 Always Below 1 Ω
      1B-7 - Body ground Always Below 1 Ω
      Positive (+) battery cable - 1C-1 Always Below 1 Ω
      Positive (+) battery cable - AM2 fuse terminal 1 Always Below 1 Ω
      J9-5 (AM2) - AM2 fuse terminal 2 Always Below 1 Ω
      J9-6 (IG2) - 1B-6 Always Below 1 Ω
      A24-28 (IGSW) or 1B-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 1C-1 - Body ground Always 10 kΩ or higher
      J9-5 (AM2) or AM2 fuse terminal 2 - Body ground Always 10 kΩ or higher
      J9-6 (IG2) or 1B-6 - Body ground Always 10 kΩ or higher
      Fig 5: Identifying A24 ECM And J9 Ignition Switch Connector
      G05149952Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  6. INSPECT IGNITION SWITCH  (see INSPECTION PROCEDURE )

    NG: REPLACE IGNITION SWITCH  (See REMOVAL )

    OK: Go to next step 

  7. CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY - ECM, BATTERY AND BODY GROUND) 
    1. Disconnect the A24 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 

      INTEGRATION RELAY - ECM, BATTERY AND BODY GROUND

      Tester Connection Condition Specified Condition
      A24-3(+B) - 1B-4 Always Below 1 Ω
      A24-2(+B2) - 1B-4 Always Below 1 Ω
      A24-34(MREL) - 1B-2 Always Below 1 Ω
      1C-1 - Positive (+) battery cable Always Below 1 Ω
      1B-3 - Body ground Always Below 1 Ω
      A24-3 (+B) or 1B-4 - Body ground Always 10 kΩ or higher
      A24-2 (+B2) or 1B-4 - Body ground Always 10 kΩ or higher
      A24-34 (MREL) or 1B-2 - Body ground Always 10 kΩ or higher
      1C-1 or Positive (+) battery cable - Body ground Always 10 kΩ or higher
      Fig 6: Identifying A24 ECM Connector Terminal And J9 Ignition Switch Connector Terminal
      G05149953Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: REPAIR OR REPLACE ENGINE ROOM RELAY BLOCK 

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