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ECM Power Source Circuit [08/2019 - ]: Procedure

  1. CHECK NO. 1 INTEGRATION RELAY (POWER SOURCE) 
    GTY627536Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Remove the No. 1 integration relay from the engine room relay block.
    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

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

      *1 Engine Room Relay Block
      *a Front view of wire harness connector
      (to No. 1 Integration Relay)

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR (NO. 1 INTEGRATION RELAY - BATTERY) 

    Result: 

    OK 

    See step  2

  2. INSPECT NO. 1 INTEGRATION RELAY (EFI MAIN) 
    1. Inspect the No. 1 integration relay (EFI MAIN) (Refer to PROCEDURE - Step 3 ).

    Result: 

    NG 

    REPLACE NO. 1 INTEGRATION RELAY 

    (Refer to PROCEDURE - Step 2 )

    Result: 

    OK 

    See step  3

  3. CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - ECM, BODY GROUND) 
    1. Check the harness and connectors between the No. 1 integration relay and ECM.
      1. Remove the No. 1 integration relay from the engine room relay block.
      2. Disconnect the ECM connector.
      3. Measure the resistance according to the value(s) in the table below.

        Standard Resistance

        Tester Connection Condition Specified Condition
        G44-9 (MREL) - 1B-2 Always Below 1 Ω
        G44-22 (+B) - 1B-4 Always Below 1 Ω
        G44-23 (+B2) - 1B-4 Always Below 1 Ω
        G44-9 (MREL) or 1B-2 - Body ground Always 10 kΩ or higher
        G44-22 (+B) or 1B-4 - Body ground Always 10 kΩ or higher
        G44-23 (+B2) or 1B-4 - Body ground Always 10 kΩ or higher
    2. Check the harness and connectors between the No. 1 integration relay and body ground.
      1. Measure the resistance according to the value(s) in the table below.

        Standard Resistance

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

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  4

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

      Standard Resistance

      Tester Connection Condition Specified Condition
      C30-12 (E1) - Body ground Always Below 1 Ω

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  5

  5. INSPECT ECM (IGSW VOLTAGE) 
    GTY681412Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Disconnect the ECM connectors.
    2. Turn the engine switch on (IG).
    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Switch Condition Specified Condition
      G45-21 (IGSW) - C30-12 (E1) Engine switch on (IG) 11 to 14 V
      TEXT IN ILLUSTRATION

      *a Rear view of wire harness connector
      (to ECM)

    Result: 

    OK 

    REPLACE ECM 

    (Refer to REMOVAL [08/2015 - ] )

    Result: 

    NG 

    See step  6

  6. INSPECT NO. 1 INTEGRATION RELAY (IG2) 
    1. Inspect the No. 1 integration relay (IG2) (Refer to PROCEDURE - Step 2 ).

    Result: 

    NG 

    REPLACE NO. 1 INTEGRATION RELAY 

    (Refer to PROCEDURE - Step 2 )

    Result: 

    OK 

    See step  7

  7. CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - ECM) 
    1. Remove the No. 1 integration relay from the engine room relay block.
    2. Disconnect the ECM connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      1A-5 - G45-21 (IGSW) Always Below 1 Ω
      1A-5 or G45-21 (IGSW) - Body ground Always 10 kΩ or higher
      RESULT

      Result Proceed to
      Out of normal range A
      Within normal range B

    Result: 

    A 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    B 

    See step  8

  8. CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)) 
    1. Remove the No. 1 integration relay from the engine room relay block.
    2. Disconnect the certification ECU (smart key ECU assembly).
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      1A-1 - G111-3 (IG1D) Always Below 1 Ω
      1A-3 - Body ground Always Below 1 Ω
      G111-3 (IG1D) - Body ground Always 10 kΩ or higher

    Result: 

    OK 

    CHECK SMART ACCESS SYSTEM WITH PUSH-BUTTON START 

    (Refer to HOW TO PROCEED WITH TROUBLESHOOTING [08/2019 - 08/2022] , or refer to HOW TO PROCEED WITH TROUBLESHOOTING [08/2022 - ] )

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

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