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ECM Power Source Circuit [02/2017 - ]: Procedure

  1. CHECK HARNESS AND CONNECTOR (ECM - BODY GROUND) 
    1. Disconnect the C63 ECM connector.
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      C63-59 (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 (IGSW TERMINAL VOLTAGE) 
    1. Disconnect the ECM connector.
      GTY765196Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to ECM)
    2. Turn the ignition switch to ON.
    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Switch Condition Specified Condition
      A38-6 (IGSW) - Body ground Ignition switch ON 11 to 14 V

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  7

    Result: 

    OK 

    See step  3

  3. INSPECT EFI-MAIN NO. 1 RELAY 
    1. Inspect the EFI-MAIN NO. 1 relay.

      Refer to PROCEDURE - Step 1

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPLACE EFI-MAIN NO. 1 RELAY 

    Result: 

    OK 

    See step  4

  4. CHECK HARNESS AND CONNECTOR (ECM - EFI-MAIN NO. 1 RELAY) 
    1. Disconnect the A38 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
      A38-46 (MREL) - 1 (EFI-MAIN NO. 1 relay holder) Always Below 1 Ω
      A38-2 (+B) - 3 (EFI-MAIN NO. 1 relay holder) Always Below 1 Ω
      A38-3 (+B2) - 3 (EFI-MAIN NO. 1 relay holder) Always Below 1 Ω
      A38-46 (MREL) or 1 (EFI-MAIN NO. 1 relay holder) - Body ground and other terminals Always 10 kΩ or higher
      A38-2 (+B) or 3 (EFI-MAIN NO. 1 relay holder) - Body ground and other terminals Always 10 kΩ or higher
      A38-3 (+B2) or 3 (EFI-MAIN NO. 1 relay holder) - Body ground and other terminals Always 10 kΩ or higher

      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.
      GTY769476Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 No. 1 Engine Room Relay Block
      *2 EFI-MAIN NO. 1 Relay Holder
    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

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

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

    Result: 

    OK 

    See step  6

  6. CHECK HARNESS AND CONNECTOR (EFI-MAIN NO. 1 RELAY - BODY GROUND) 
    1. Remove the EFI-MAIN NO. 1 relay from the No. 1 engine room relay block.
      GTY769476Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 No. 1 Engine Room Relay Block
      *2 EFI-MAIN NO. 1 Relay Holder
    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

      Proceed to
      OK
      NG

    Result: 

    OK 

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  7. INSPECT NO. 1 INTEGRATION RELAY 
    1. Inspect the No. 1 integration relay.

      Refer to PROCEDURE - Step 1

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPLACE NO. 1 INTEGRATION RELAY. Refer to  REMOVAL [02/2017 - 08/2020]  , or refer to  REMOVAL [08/2020 - ] 

    Result: 

    OK 

    See step  8

  8. CHECK HARNESS AND CONNECTOR (ECM - NO. 1 INTEGRATION RELAY) 
    1. Disconnect the A38 ECM connector.
    2. Disconnect the 1A No. 1 integration relay connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      A38-6 (IGSW) - 1A-9 Always Below 1 Ω
      A38-6 (IGSW) or 1A-9 - Body ground and other terminals Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  9

  9. CHECK TERMINAL VOLTAGE (POWER SOURCE OF NO. 1 INTEGRATION RELAY) 
    1. Disconnect the No. 1 integration relay connector.
      GTY764902Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector (to No. 1 integration relay)
    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      1A-10 - Body ground Always 11 to 14 V

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

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

    Result: 

    OK 

    See step  10

  10. CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - BODY GROUND) 
    GTY764902Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    *a Front view of wire harness connector (to No. 1 integration relay)
    1. Disconnect the No. 1 integration relay connector.
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      1A-8 - Body ground Always Below 1 Ω

      Result

      Result Proceed to
      OK (w/ Smart Key System) A
      OK (w/o Smart Key System) B
      NG C

    Result: 

    B 

    See step  12

    Result: 

    C 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    A 

    See step  11

  11. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - NO. 1 INTEGRATION RELAY) 
    1. Disconnect the F1 certification ECU (smart key ECU assembly) connector.
    2. Disconnect the 1A No. 1 integration relay connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      F1-17 (IG1D) - 1A-7 Always Below 1 Ω
      F1-17 (IG1D) or 1A-7 - Body ground and other terminals Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    GO TO SMART KEY SYSTEM. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [02/2017 - ] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  12. INSPECT IGNITION OR STARTER SWITCH ASSEMBLY 
    1. Inspect the ignition switch assembly.

      Refer to INSPECTION [02/2017 - ]

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPLACE IGNITION OR STARTER SWITCH ASSEMBLY 

    Result: 

    OK 

    See step  13

  13. CHECK HARNESS AND CONNECTOR (IGNITION SWITCH ASSEMBLY - NO. 1 INTEGRATION RELAY) 
    1. Disconnect the F12 ignition switch assembly connector.
    2. Disconnect the 1A No. 1 integration relay connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      F12-8 (IG1) - 1A-7 Always Below 1 Ω
      F12-8 (IG1) or 1A-7 - Body ground and other terminals Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

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

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

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