FixVault
Home › Toyota › 2008 › Tundra Base, 5.7 V, RWD › Repair and Diagnosis › Engine Performance › Engine Control Systems › Engine Control System (3UR-FE) - System Testing, On-Vehicle Inspection, Removal, Inspection & Installation › ECM Power Source Circuit › Inspection Procedure

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 

      STANDARD RESISTANCE SPECIFICATION

      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

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

    Fig 1: Identifying AM2 Fuse & IGN Fuse From Engine Room Relay Block
    G05681638Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    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 

      STANDARD RESISTANCE SPECIFICATION

      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-6 and 1B-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-4 When battery voltage Is applied to terminals 1B-2 and 1B-3 Below 1 Ω
      Fig 2: Identifying Integration Relay Connector Terminals
      G05681639Courtesy 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 

      STANDARD RESISTANCE SPECIFICATION

      Tester Connection Condition Specified Condition
      D74-81 (E1) - Body ground Always Below 1 Ω

    NG : REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Fig 3: Identifying D74 ECM Connector Terminals
    G05681640Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK : Go to next step 

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

      Standard voltage 

      STANDARD VOLTAGE SPECIFICATION

      Tester Connection Switch Condition Specified Condition
      A24-28 (IGSW) - D74-81 (E1) Ignition switch ON 11 to 14 V

    NG : Go to step 5 

    Fig 4: Identifying D74, A24 ECM Connector Terminals
    G05681641Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    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 

      STANDARD RESISTANCE SPECIFICATION

      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

    NG : REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Fig 5: Checking Harness & Connector (Relay Block - ECM, Ignition Switch, Battery & Body Ground)
    G05681642Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK : Go to next step 

  6. INSPECT IGNITION SWITCH  (See INSPECTION PROCEDURE )

    NG : REPLACE IGNITION SWITCH  . (See IGNITION SWITCH ).

    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 

      STANDARD RESISTANCE SPECIFICATION

      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

    NG : REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Fig 6: Identifying A24 ECM Connector Terminals
    G05681643Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK : REPAIR OR REPLACE ENGINE ROOM RELAY BLOCK 

About FixVault