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ECM Power Source Circuit [11/2022 - ]: Procedure

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  1. 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
      A47-10 (E1) - Body ground Always Below 1 Ω

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  2

  2. CHECK TERMINAL VOLTAGE (IGP TERMINAL VOLTAGE) 
    1. Disconnect the ECM connector.
    2. Turn the ignition switch to ON.
    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      A47-2 (IGP) - Body ground Ignition switch ON 11 to 14 V

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  6

    Result: 

    OK 

    See step  3

  3. INSPECT EFI-MAIN NO. 1 RELAY 

    Refer to ON-VEHICLE INSPECTION [11/2022 - ]

    Result

    Proceed to
    OK
    NG

    Result: 

    NG 

    REPLACE EFI-MAIN NO. 1 RELAY 

    Result: 

    OK 

    See step  4

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

      Standard Resistance

      Tester Connection Condition Specified Condition
      3 (EFI-MAIN NO. 1 relay) - A47-9 (+B) Always Below 1 Ω
      3 (EFI-MAIN NO. 1 relay) - A47-35 (+B2) Always Below 1 Ω
      1 (EFI-MAIN NO. 1 relay) - A47-15 (MREL) Always Below 1 Ω
      3 (EFI-MAIN NO. 1 relay) or A47-9 (+B) - Body ground and other terminals Always 10 kΩ or higher
      3 (EFI-MAIN NO. 1 relay) or A47-35 (+B2) - Body ground and other terminals Always 10 kΩ or higher
      1 (EFI-MAIN NO. 1 relay) or A47-15 (MREL) - Body ground and other terminals Always 10 kΩ or higher

      HINT: 

      If a short is detected in any of the above circuits, there may be a malfunction in the circuit of a connected ECU.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  5

  5. CHECK TERMINAL VOLTAGE (POWER SOURCE OF EFI-MAIN NO. 1 RELAY) 
    1. Remove the EFI-MAIN NO. 1 relay from the No. 1 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) - Body ground Always 11 to 14 V
      2 (EFI-MAIN NO. 1 relay) - Body ground Always 11 to 14 V

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE ECM 

    Refer to REMOVAL [11/2022 - ]

    Result: 

    NG 

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

  6. INSPECT IGP-MAIN RELAY 
    1. Remove the IGP-MAIN relay from the No. 1 engine room relay block.
    2. Measure the resistance according to the value(s) in the table below.
      GTY1104539Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 IGP-MAIN Relay

      Standard Resistance

      Tester Connection Condition Specified Condition
      3 - 5 Auxiliary battery voltage not applied between terminals 1 and 2 10 kΩ or higher
      Auxiliary battery voltage applied between terminals 1 and 2 Below 1 Ω
    3. Install the IGP-MAIN relay.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPLACE IGP-MAIN RELAY 

    Result: 

    OK 

    See step  7

  7. CHECK HARNESS AND CONNECTOR (IGP-MAIN RELAY - ECM) 
    1. Remove the IGP-MAIN relay from the No. 1 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
      3 (IGP-MAIN Relay) - A47-2 (IGP-MAIN) Always Below 1 Ω
      3 (IGP-MAIN Relay) or A47-2 (IGP-MAIN) - Body ground and other terminals Always 10 kΩ or higher

      HINT: 

      If a short is detected in any of the above circuits, there may be a malfunction in the circuit of a connected ECU.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  8

  8. CHECK TERMINAL VOLTAGE (POWER SOURCE OF IGP-MAIN RELAY) 
    1. Remove the IGP-MAIN relay from the No. 1 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 (IGP-MAIN relay) - Body ground Always 11 to 14 V

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR (AUXILIARY BATTERY - IGP-MAIN RELAY) 

    Result: 

    OK 

    See step  9

  9. CHECK HARNESS AND CONNECTOR (IGP-MAIN RELAY - BODY GROUND) 
    1. Remove the IGP-MAIN relay from the No. 1 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 (IGP-MAIN relay) - Body ground Always Below 1 Ω

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  10

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

      Standard Resistance

      Tester Connection Condition Specified Condition
      I223-24 (IGPD) - 2 (IGP-MAIN relay) Always Below 1 Ω
      I223-24 (IGPD) or 2 (IGP-MAIN relay) - Body ground and other terminals Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    GO TO SMART KEY SYSTEM (FOR START FUNCTION) 

    Refer to HOW TO PROCEED WITH TROUBLESHOOTING [11/2022 - ]

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

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