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ECM Power Source Circuit [11/2017 - ]: Procedure

WARNING: This page is about a different variant/trim than selected.
  1. CHECK TERMINAL VOLTAGE (+B, +B2 VOLTAGE) 
    GTY757429Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Turn the ignition switch to ON.
    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Switch Condition Specified Condition
      E21-1 (+B) - E17-3 (E1) Ignition switch ON 11 to 14 V
      E21-2 (+B2) - E17-3 (E1) Ignition switch ON 11 to 14 V
      TEXT IN ILLUSTRATION

      *a Component with harness connected
      (ECM)

    Result: 

    OK 

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE 

    (Refer to PROBLEM SYMPTOMS TABLE [11/2017 - ] )

    Result: 

    NG 

    See step  2

  2. CHECK HARNESS AND CONNECTOR (ECM - BODY GROUND) 
    1. Disconnect the E17 ECM connector.
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      E17-3 (E1) - Body ground Always Below 1 Ω

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  3

  3. CHECK TERMINAL VOLTAGE (IGSW VOLTAGE) 
    GTY772250Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Turn the ignition switch to ON.
    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Switch Condition Specified Condition
      E21-8 (IGSW) - E17-3 (E1) Ignition switch ON 11 to 14 V
      TEXT IN ILLUSTRATION

      *a Component with harness connected
      (ECM)

    Result: 

    NG 

    See step  9

    Result: 

    OK 

    See step  4

  4. CHECK TERMINAL VOLTAGE (MREL VOLTAGE) 
    GTY757430Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Turn the ignition switch to ON.
    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Switch Condition Specified Condition
      E20-6 (MREL) - E17-3 (E1) Ignition switch ON 11 to 14 V
      TEXT IN ILLUSTRATION

      *a Component with harness connected
      (ECM)

    Result: 

    NG 

    REPLACE ECM 

    (Refer to REMOVAL [11/2017 - 09/2019] , or refer to REMOVAL [09/2019 - ] )

    Result: 

    OK 

    See step  5

  5. INSPECT EFI-MAIN NO. 1 RELAY 
    1. Inspect the EFI-MAIN NO. 1 relay (Refer to PROCEDURE - Step 1 ).

    Result: 

    NG 

    REPLACE EFI-MAIN NO. 1 RELAY 

    Result: 

    OK 

    See step  6

  6. CHECK TERMINAL VOLTAGE (POWER SOURCE OF EFI-MAIN NO. 1 RELAY) 
    GTY545038Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Remove the EFI-MAIN NO. 1 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
      5 (EFI-MAIN NO. 1 relay holder) - Body ground Always 11 to 14 V
      TEXT IN ILLUSTRATION

      *1 Engine Room Relay Block
      *2 EFI-MAIN NO. 1 Relay Holder

    Result: 

    NG 

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

    Result: 

    OK 

    See step  7

  7. CHECK HARNESS AND CONNECTOR (EFI-MAIN NO. 1 RELAY - BODY GROUND) 
    1. Remove the EFI-MAIN NO. 1 relay from the engine room relay block.
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      2 (EFI-MAIN NO. 1 relay holder) - Body ground Always Below 1 Ω

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  8

  8. CHECK HARNESS AND CONNECTOR (EFI-MAIN NO. 1 RELAY - ECM) 
    1. Remove the EFI-MAIN NO. 1 relay from the engine room relay block.
    2. Disconnect the E20 and E21 ECM connectors.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      1 (EFI-MAIN NO. 1 relay holder) - E20-6 (MREL) Always Below 1 Ω
      3 (EFI-MAIN NO. 1 relay holder) - E21-1 (+B) Always Below 1 Ω
      3 (EFI-MAIN NO. 1 relay holder) - E21-2 (+B2) Always Below 1 Ω
      1 (EFI-MAIN NO. 1 relay holder) or E20-6 (MREL) - Body ground Always 10 kΩ or higher
      3 (EFI-MAIN NO. 1 relay holder) or E21-1 (+B) - Body ground Always 10 kΩ or higher
      3 (EFI-MAIN NO. 1 relay holder) or E21-2 (+B2) - Body ground Always 10 kΩ or higher

    Result: 

    OK 

    REPLACE ECM 

    (Refer to REMOVAL [11/2017 - 09/2019] , or refer to REMOVAL [09/2019 - ] )

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  9. INSPECT IG2-MAIN RELAY 
    1. Inspect the IG2-MAIN relay.

    Result: 

    NG 

    REPLACE IG2-MAIN RELAY 

    Result: 

    OK 

    See step  10

  10. CHECK TERMINAL VOLTAGE (POWER SOURCE OF IG2-MAIN RELAY) 
    GTY539174Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Remove the IG2-MAIN 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
      5 (IG2-MAIN relay holder) - Body ground Always 11 to 14 V
      TEXT IN ILLUSTRATION

      *1 Engine Room Relay Block
      *2 IG2-MAIN Relay Holder

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR (IG2-MAIN RELAY - BATTERY) 

    Result: 

    OK 

    See step  11

  11. CHECK TERMINAL VOLTAGE (POWER SOURCE OF IG2-MAIN RELAY) 
    GTY539174Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Remove the IG2-MAIN relay from the engine room relay block.
    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Switch Condition Specified Condition
      1 (IG2-MAIN relay holder) - Body ground Ignition switch ON 11 to 14 V
      TEXT IN ILLUSTRATION

      *1 Engine Room Relay Block
      *2 IG2-MAIN Relay Holder

    Result: 

    NG 

    See step  14

    Result: 

    OK 

    See step  12

  12. CHECK HARNESS AND CONNECTOR (IG2-MAIN RELAY - BODY GROUND) 
    1. Remove the IG2-MAIN relay from the engine room relay block.
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      2 (IG2-MAIN relay holder) - Body ground Always Below 1 Ω

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  13

  13. CHECK HARNESS AND CONNECTOR (IG2-MAIN RELAY - ECM) 
    1. Remove the IG2-MAIN relay from the engine room relay block.
    2. Disconnect the E21 ECM connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      3 (IG2-MAIN relay holder) - E21-8 (IGSW) Always Below 1 Ω
      3 (IG2-MAIN relay holder) or E21-8 (IGSW) - Body ground Always 10 kΩ or higher

    Result: 

    OK 

    REPLACE ECM 

    (Refer to REMOVAL [11/2017 - 09/2019] , or refer to REMOVAL [09/2019 - ] )

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  14. INSPECT IGNITION OR STARTER SWITCH ASSEMBLY 
    1. Inspect the ignition or starter switch assembly (Refer to INSPECTION [08/2015 - ] ).

    Result: 

    NG 

    REPLACE IGNITION OR STARTER SWITCH ASSEMBLY 

    (Refer to REMOVAL [08/2015 - ] )

    Result: 

    OK 

    See step  15

  15. CHECK HARNESS AND CONNECTOR (IG2-MAIN RELAY - IGNITION OR STARTER SWITCH ASSEMBLY) 
    1. Remove the IG2-MAIN relay from the engine room relay block.
    2. Disconnect the I7 ignition or starter switch assembly connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      1 (IG2-MAIN relay holder) - I7-3 (IG2) Always Below 1 Ω
      1 (IG2-MAIN relay holder) or I7-3 (IG2) - Body ground Always 10 kΩ or higher

    Result: 

    OK 

    REPAIR OR REPLACE HARNESS OR CONNECTOR (IGNITION OR STARTER SWITCH ASSEMBLY - BATTERY) 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

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