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Home >> Toyota >> 2009 >> Tundra Base, 4.0 U >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (1GR-FE) - System And Circuit Testing, On-Vehicle Inspection, Removal, Inspection & Installation >> ECM Power Source Circuit >> Inspection Procedure

Inspection Procedure

  1. CHECK HARNESS AND CONNECTOR (BATTERY - INTEGRATION RELAY) 
    1. Remove the integration relay from the engine room junction block (See ON-VEHICLE INSPECTION  ).
    2. Measure the voltage according to the value(s) in the table below.

      Standard voltage 

      TESTER CONNECTION SPECIFIED CONDITION

      Tester Connection Condition Specified Condition
      1C-1 - Body ground Always 11 to 14 V

      NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

      Fig 1: Identifying Engine Room Junction Block Connector Terminal
      G06227596Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      OK: Go to next step 

  2. INSPECT INTEGRATION RELAY (EFI RELAY AND IG2 RELAY) 
    1. Remove the integration relay from the engine room relay block (See ON-VEHICLE INSPECTION  ).
    2. Inspect the EFI NO. 1 fuse and the IG2 MAIN fuse.
      1. Remove the EFI NO. 1 fuse and IG2 MAIN fuse from the integration relay.
      2. Measure the resistance according to the value(s) in the table below.

        Standard resistance 

        TESTER CONNECTION SPECIFIED CONDITION

        Tester Connection Condition Specified Condition
        EFI NO. 1 fuse Always Below 1 Ω
        IG2 MAIN fuse Always Below 1 Ω
    3. Inspect the EFI relay and the IG2 relay.
      1. Measure the resistance according to the value(s) in the table below.
        Fig 2: Identifying EFI NO. 1 Fuse And IG2 MAIN Fuse
        G06227597Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

        Standard resistance 

        TESTER CONNECTION SPECIFIED CONDITION

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

        NG: REPLACE INTEGRATION RELAY  (See ON-VEHICLE INSPECTION  )

        OK: Go to next step 

  3. CHECK HARNESS AND CONNECTOR (+B, +B2 AND MREL CIRCUIT) 
    1. Check the harness and the connectors between the integration relay and the ECM.
      1. Remove the integration relay from the engine room junction block (See ON-VEHICLE INSPECTION  ).
      2. Disconnect the A24 ECM connector.
      3. Measure the resistance according to the value(s) in the table below.

        Standard resistance (Check for open) 

        TESTER CONNECTION SPECIFIED CONDITION

        Tester Connection Condition Specified Condition
        A24-34 (MREL) - 1B-2 Always Below 1 Ω
        A24-3 (+B) - 1B-4 Always Below 1 Ω
        A24-2 (+B2) - 1B-4 Always Below 1 Ω

        Standard resistance (Check for short) 

        TESTER CONNECTION SPECIFIED CONDITION

        Tester Connection Condition Specified Condition
        A24-34 (MREL) or 1B-2 - Body ground Always 10 kΩ or higher
        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
    2. Check the harness and connectors between the integration relay and body ground.
      1. Measure the resistance according to the value(s) in the table below.

        Standard resistance (Check for open) 

        TESTER CONNECTION SPECIFIED CONDITION

        Tester Connection Condition Specified Condition
        1B-3 - Body ground Always Below 1 Ω

        NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

        Fig 3: Identifying ETCS Fuse And D74 ECM Connector Terminals
        G06227598Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

        OK: Go to next step 

  4. 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 (Check for open) 

      TESTER CONNECTION SPECIFIED CONDITION

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

      NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

      Fig 4: Identifying D74 ECM Connector Terminal
      G06227599Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      OK: Go to next step 

  5. INSPECT ECM (IGSW VOLTAGE) 
    1. Disconnect the D74 and A24 ECM connectors.
    2. Measure the voltage according to the value(s) in the table below.

      Standard voltage 

      TESTER CONNECTION SPECIFIED CONDITION

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

      NG: Go to step 6 

      Fig 5: Identifying D74 And A24 ECM Connector Terminal
      G06227600Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      OK: REPLACE ECM  (See REMOVAL  )

  6. INSPECT FUSE (IGN) 
    1. Remove the IGN fuse from the engine room relay block.
    2. Measure the resistance according to the value(s) in the table below.

      Standard resistance (Check for open) 

      TESTER CONNECTION SPECIFIED CONDITION

      Tester Connection Condition Specified Condition
      IGN fuse Always Below 1 Ω

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

      Fig 6: Identifying IGN Fuse And Engine Room Relay Block
      G06227601Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      OK: Go to next step 

  7. CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY - ECM, INTEGRATION RELAY - BODY GROUND) 
    1. Remove the integration relay from the engine room junction block (See ON-VEHICLE INSPECTION  ).
    2. Disconnect the A24 ECM connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard resistance (Check for open) 

      TESTER CONNECTION SPECIFIED CONDITION

      Tester Connection Condition Specified Condition
      1B-8 - A24-28 (IGSW) Always Below 1 Ω

      Standard resistance (Check for short) 

      TESTER CONNECTION SPECIFIED CONDITION

      Tester Connection Condition Specified Condition
      1B-8 or A24-28 (IGSW) - Body ground Always 10 kΩ or higher

      NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

      Fig 7: Identifying A24 ECM Connector Terminal
      G06227602Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      OK: Go to next step 

  8. CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY - IGNITION SWITCH ASSEMBLY) 
    1. Check the harness and the connectors between the integration relay and the ignition switch.
      1. Remove the integration relay from the engine room junction block (See ON-VEHICLE INSPECTION  ).
      2. Disconnect the J9 ignition switch connector.
      3. Measure the resistance according to the value(s) in the table below.

        Standard resistance (Check for open) 

        TESTER CONNECTION SPECIFIED CONDITION

        Tester Connection Condition Specified Condition
        1B-6 - J9-6 (IG2) Always Below 1 Ω

        Standard resistance (Check for short) 

        TESTER CONNECTION SPECIFIED CONDITION

        Tester Connection Condition Specified Condition
        1B-6 or J9-6 (IG2) - Body ground Always 10 kΩ or higher
    2. Check the harness and connectors between the integration relay and body ground.
      1. Measure the resistance according to the value(s) in the table below.

        Standard resistance (Check for open) 

        TESTER CONNECTION SPECIFIED CONDITION

        Tester Connection Condition Specified Condition
        1B-7 - Body ground Always Below 1 Ω

        NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

        Fig 8: Identifying Integration Relay And Body Ground
        G06227603Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

        OK: Go to next step 

  9. INSPECT IGNITION SWITCH ASSEMBLY 
    1. Disconnect the J9 ignition switch connector.
    2. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      TESTER CONNECTION SPECIFIED CONDITION

      Tester Connection Switch Condition Specified Condition
      All Terminals Ignition switch position LOCK 10 kΩ or higher
      2 (ACC) - 4 (AM1) Ignition switch position ACC Below 1 Ω
      1 (IG1) - 2(ACC) - 4 (AM1) Ignition switch position ON
      5 (AM2) - 6 (IG2)
      1 (IG1) - 3 (ST1) - 4 (AM1) Ignition switch position START
      5 (AM2) - 6 (IG2) - 7 (ST2)

      NG: REPLACE IGNITION SWITCH ASSEMBLY (See  REMOVAL  ) 

      Fig 9: Identifying Ignition Switch Connector
      G06227604Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      OK: REPAIR OR REPLACE HARNESS OR CONNECTOR 

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