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Home >> Lexus >> 2011 >> RX 350 AWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System SFI System [2GR-FE] (Diagnostic Codes & Circuit Tests) >> SFI System >> Circuit Tests >> ECM Power Source Circuit >> Procedure
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ECM Power Source Circuit: Procedure

  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
      D1-81 (E1) - Body ground Always Below 1 Ω
    3. Reconnect the ECM connector.

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (ECM - BODY GROUND) 

    OK: Go to next step 

  2. INSPECT ECM (IGSW VOLTAGE) 
    1. Disconnect the ECM connector.
      Fig 1: ECM Connector
      GTY348890Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    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
      A43-28 (IGSW) - Body ground Engine switch on (IG) 11 to 14 V
      TEXT IN ILLUSTRATION

      *a Front view of wire harness connector
      (to ECM)
    4. Reconnect the ECM connector.

    NG → See step   7 

    OK: Go to next step 

  3. INSPECT RELAY (EFI MAIN RELAY) 
    1. Remove the EFI MAIN relay from the engine room relay block.
      Fig 2: Inspecting ENG W/P Relay
      GTY357514Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      3 - 5 No battery voltage applied to terminals 1 and 2 10 kΩ or higher
      Battery voltage applied to terminals 1 and 2 Below 1 Ω
    3. Reinstall the EFI MAIN relay relay.

    NG → REPLACE RELAY (EFI MAIN RELAY) 

    OK: Go to next step 

  4. CHECK HARNESS AND CONNECTOR (EFI MAIN RELAY) 
    1. Remove the EFI MAIN 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 (Check for Open)

      Tester Connection Condition Specified Condition
      3 (EFI MAIN relay terminal) - A43-3 (+B) Always Below 1 Ω
      3 (EFI MAIN relay terminal) - A43-2 (+B2) Always Below 1 Ω
      1 (EFI MAIN relay terminal) - A43-34 (MREL) Always Below 1 Ω

      Standard Resistance (Check for Short)

      Tester Connection Condition Specified Condition
      3 (EFI MAIN relay terminal) or A43-3 (+B) - Body ground Always 10 kΩ or higher
      3 (EFI MAIN relay terminal) or A43-2 (+B2) - Body ground Always 10 kΩ or higher
      1 (EFI MAIN relay terminal) or A43-34 (MREL) - Body ground Always 10 kΩ or higher
    4. Reconnect the ECM connector.
    5. Reinstall the EFI MAIN relay block assembly.

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (EFI MAIN RELAY - ECM) 

    OK: Go to next step 

  5. CHECK HARNESS AND CONNECTOR (BATTERY - EFI MAIN RELAY) 
    1. Remove the EFI MAIN relay from the engine room relay block.
    2. Disconnect the cable from the negative (-) battery terminal.
    3. Disconnect the cable from the positive (+) battery terminal.
    4. Measure the resistance according to the value(s) in the table below.

      Standard Resistance (Check for Open)

      Tester Connection Condition Specified Condition
      5 (EFI MAIN relay terminal) - Battery positive (+) terminal Always Below 1 Ω

      Standard Resistance (Check for Short)

      Tester Connection Condition Specified Condition
      5 (EFI MAIN relay terminal) - Body ground Always 10 kΩ or higher
    5. Reinstall the EFI MAIN relay.
    6. Reconnect the cable to the positive (+) battery terminal.
    7. Reconnect the cable to the negative (-) battery terminal.

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (BATTERY - EFI MAIN RELAY) 

    OK: Go to next step 

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

      Standard Resistance (Check for Open)

      Tester Connection Condition Specified Condition
      2 (EFI MAIN relay terminal) - Body ground Always Below 1 Ω
    3. Reinstall the EFI MAIN relay.

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (EFI MAIN RELAY - BODY GROUND) 

    OK → See step   12 

  7. INSPECT RELAY (IG2 RELAY) 
    1. Remove the IG2 relay from the engine room relay block.
      Fig 3: Inspecting ENG W/P Relay
      GTY357514Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      3 - 5 No battery voltage applied to terminals 1 and 2 10 kΩ or higher
      3 - 5 Battery voltage applied to terminals 1 and 2 Below 1 Ω
    3. Reinstall the IG2 relay.

    NG → REPLACE RELAY (IG2 RELAY) 

    OK: Go to next step 

  8. CHECK HARNESS AND CONNECTOR (IG2 RELAY - ECM) 
    1. Remove the IG2 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 (Check for Open)

      Tester Connection Condition Specified Condition
      3 (IG2 relay terminal) - A43-28 (IGSW) Always Below 1 Ω

      Standard Resistance (Check for Short)

      Tester Connection Condition Specified Condition
      3 (IG2 relay terminal) or A43-28 (IGSW) - Body ground Always 10 kΩ or higher
    4. Reinstall the IG2 relay.
    5. Reconnect the ECM connector.

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (IG2 RELAY - ECM) 

    OK: Go to next step 

  9. CHECK HARNESS AND CONNECTOR (IG2 RELAY POWER SOURCE) 
    1. Remove the IG2 relay from the engine room relay block.
      Fig 4: IG2 Relay
      GTY358650Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      5 (IG2 relay terminal) - Body ground Always 11 to 14 V
      TEXT IN ILLUSTRATION

      *1 Engine Room Relay Block
    3. Reinstall the IG2 relay.

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (IG2 RELAY - BATTERY) 

    OK: Go to next step 

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

      Standard Resistance (Check for Open)

      Tester Connection Condition Specified Condition
      2 (IG2 relay terminal) - Body ground Always Below 1 Ω
    3. Reinstall the IG2 relay.

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (IG2 RELAY - BODY GROUND) 

    OK: Go to next step 

  11. CHECK HARNESS AND CONNECTOR (IG2 RELAY - POWER MANAGEMENT CONTROL ECU) 
    1. Disconnect the power management control ECU connector.
    2. Remove the IG2 relay from the engine room relay block.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance (Check for Open)

      Tester Connection Condition Specified Condition
      1 (IG2 relay terminal) - F7-8 (IG2D) Always Below 1 Ω

      Standard Resistance (Check for Short)

      Tester Connection Condition Specified Condition
      1 (IG2 relay terminal) or F7-8 (IG2D) - Body ground Always 10 kΩ or higher
    4. Reconnect the power management control ECU connector.
    5. Reinstall the IG2 relay.

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (IG2 RELAY - POWER MANAGEMENT CONTROL ECU) 

    OK → See step   13 

  12. PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to  PROBLEM SYMPTOMS TABLE 
  13. GO TO SMART ACCESS SYSTEM WITH PUSH-BUTTON START. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING 
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