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ECM Power Source Circuit: Procedure

  1. INSPECT ECM (+B, +B1 VOLTAGE) 
    1. Turn the engine switch on (IG).
      Fig 1: Identifying E4 And A5 ECM Connector
      GTY123102Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the voltage according to the value(s) in the table below.

      Standard voltage

      Tester Connection Specified Condition
      +B (A5-6) - E1 (E4-7) 9 to 14 V
      +B1 (A5-5) - E1 (E4-7) 9 to 14 V

    OK → PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE 

    NG: Go to next step 

  2. CHECK HARNESS AND CONNECTOR (ECM - BODY GROUND) 
    1. Disconnect the E4 ECM connector.
      Fig 2: Identifying E4 ECM Connector
      GTY127297Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance according to the value(s) in the table below.

      Standard resistance (Check for open)

      Tester Connection Specified Condition
      E1 (E4-7) - Body ground Below 1 Ω
    3. Reconnect the ECM connector.

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  3. INSPECT ECM (IGSW VOLTAGE) 
    1. Turn the engine switch on (IG).
      Fig 3: Identifying E4 And A5 ECM Connector
      GTY146222Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the voltage according to the value(s) in the table below.

      Standard voltage

      Tester Connection Specified Condition
      IGSW (A5-17) - E1 (E4-7) 9 to 14 V

    OK → See step   6 

    NG: Go to next step 

  4. CHECK FUSE (IGN FUSE) 
    1. Remove the IGN fuse from the cowl side junction block RH.
      Fig 4: Identifying IGN Fuse
      GTY104671Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance of the IGN fuse.

      Standard resistance

      Below 1 Ω

    3. Reinstall the IGN fuse.

    NG → REPLACE FUSE 

    OK: Go to next step 

  5. INSPECT IGNITION RELAY NO. 2 
    1. Remove the IG2 relay from the engine room R/B No. 2.
      Fig 5: Inspecting Ignition Relay No. 2 (IG2)
      GTY100984Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance according to the value(s) in the table below.

      Standard resistance

      Tester Connection Specified Condition
      3 - 5 10 kΩ or higher
      3 - 5 Below 1 Ω
      (when battery voltage applied to terminals 1 and 2)

    NG → REPLACE IGNITION RELAY NO. 2 

    OK → CHECK AND REPLACE SMART ACCESS SYSTEM WITH PUSH-BUTTON START 

  6. INSPECT ECM (MREL VOLTAGE) 
    1. Turn the engine switch on (IG).
      Fig 6: Identifying E4 And A5 ECM Connector
      GTY122741Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the voltage according to the value(s) in the table below.

      Standard voltage

      Tester Connection Specified Condition
      MREL (A5-13) - E1 (E4-7) 9 to 14 V

    NG → REPLACE ECM 

    OK: Go to next step 

  7. CHECK FUSE (EFI FUSE) 
    1. Remove the EFI fuse from the engine room J/B No. 2.
      Fig 7: Identifying EFI Fuse
      GTY134955Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance of the EFI fuse.

      Standard resistance

      Below 1 Ω

    3. Reinstall the EFI fuse.

    NG → REPLACE FUSE 

    OK: Go to next step 

  8. INSPECT INTEGRATION NO. 1 RELAY (EFI MAIN RELAY) 
    1. Remove the integration relay from the engine room J/B No. 2.
      Fig 8: Identifying Integration Relay & Terminals
      GTY145509Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance according to the value(s) in the table below.

      Standard resistance

      Tester Connection Specified Condition
      2A-5 - 2A-8 10 kΩ or higher
      Below 1 Ω
      (when battery voltage applied to terminals 2A-6 and 2A-7)

    NG → REPLACE INTEGRATION NO. 1 RELAY 

    OK: Go to next step 

  9. CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY- ECM, INTEGRATION RELAY - BODY GROUND) 
    1. Check the harness and the connectors between the integration relay and the ECM.
      Fig 9: Identifying A5 ECM Connector & Integration Relay Terminals
      GTY145653Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      1. Remove the integration relay from the engine room J/B No. 2.
      2. Disconnect the A5 ECM connector.
      3. Measure the resistance according to the value(s) in the table below.

        Standard resistance (Check for open)

        Tester Connection Specified Condition
        2A-6 - MREL (A5-13) Below 1 Ω

        Standard resistance (Check for short)

        Tester Connection Specified Condition
        2A-6 or MREL (A5-13) - Body ground 10 kΩ or higher
    2. Check the harness and the connectors between the integration relay and body ground.
      1. Remove the integration relay from the engine room J/B No. 2.
      2. Measure the resistance according to the value(s) in the table below.

        Standard resistance (Check for open)

        Tester Connection Specified condition
        2A-7 - Body ground Below 1 Ω

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK → CHECK AND REPAIR HARNESS AND CONNECTOR (TERMINAL +B OF ECM - BATTERY POSITIVE TERMINAL) 

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