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Home >> Lexus >> 2008 >> RX 350 AWD >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Engine Control System - System And Circuit Testing, On-Vehicle Inspection, Removal, Inspection & Installation >> ECM Power Source Circuit >> Inspection Procedure
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Inspection Procedure

  1. INSPECT ECM (+B VOLTAGE) 
    1. Turn the ignition switch to the ON position.
    2. Measure the voltage between the terminals of the E5 and E7 ECM connectors.

      Standard voltage 

      TESTER CONNECTION SPECIFIED CONDITION

      Tester Connection Specified Condition
      +B (E5-1) - E1 (E7-1) 9 to 14 V
      3. Fig 1: Identifying E7 And E5 Connectors Terminals
      G05268232Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN  PROBLEM SYMPTOMS TABLE 

    NG: Go to Next Step 

  2. CHECK HARNESS AND CONNECTOR (ECM - BODY GROUND) 
    1. Disconnect the E7 ECM connector.
    2. Measure the resistance between the terminal of the ECM connector and body ground.

      Standard resistance: 

      Check for open 

      TESTER CONNECTION SPECIFIED CONDITION

      Tester Connection Specified Condition
      E1 (E7-1) - Body ground Below 1 Ω
    3. Reconnect the ECM connector.
      4. Fig 2: Disconnecting E7 ECM Connector
      G05268233Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to Next Step 

  3. INSPECT ECM (IGSW VOLTAGE) 
    1. Turn the ignition switch to the ON position.
    2. Measure the voltage between the terminals of the E5 and E7 ECM connectors.

      Standard voltage 

      TESTER CONNECTION SPECIFIED CONDITION

      Tester Connection Specified Condition
      IGSW (E5-9) - E1 (E7-1) 9 to 14 V
      3. Fig 3: Identifying E7 And E5 Connectors Terminals
      G05268234Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK:  Go to step  6

    NG: Go to Next Step 

  4. CHECK FUSE (IGN FUSE) 
    1. Remove the IGN fuse from the instrument panel J/B.
    2. Measure the IGN fuse resistance.

      Standard resistance: Below 1 Ω 

    3. Reinstall the IGN fuse.
      4. Fig 4: Identifying IGN Fuse
      G05268235Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: CHECK FOR SHORTS IN ALL HARNESSES AND CONNECTORS CONNECTED TO FUSE AND REPLACE FUSE 

    OK: Go to Next Step 

  5. INSPECT IGNITION OR STARTER SWITCH ASSEMBLY 
    1. Inspect the ignition or starter switch assembly (See ON-VEHICLE INSPECTION ).

    NG: REPLACE IGNITION OR STARTER SWITCH ASSEMBLY  (See REMOVAL )

    OK: Go to Next Step 

  6. INSPECT ECM (MREL VOLTAGE) 
    1. Turn the ignition switch to the ON position.
    2. Measure the voltage between the terminals of the E5 and E7 ECM connectors.

      Standard voltage 

      TESTER CONNECTION SPECIFIED CONDITION

      Tester Connection Specified Condition
      MREL (E5-8) - E1 (E7-1) 9 to 14 V
      3. Fig 5: Identifying E7 And E5 Connectors Terminals
      G05268236Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPLACE ECM (See  REMOVAL   ) 

    OK: Go to Next Step 

  7. CHECK FUSE (EFI FUSE) 
    1. Remove the EFI No. 1 fuse from the fusible link block.
    2. Measure the EFI No. 1 fuse resistance.

      Standard resistance: Below 1 Ω 

    3. Reinstall the EFI No. 1 fuse.
      4. Fig 6: Identifying EFI No. 1 Fuse
      G05268237Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: CHECK FOR SHORTS IN ALL HARNESSES AND CONNECTORS CONNECTED TO FUSE AND REPLACE FUSE 

    OK: Go to Next Step 

  8. INSPECT EFI MAIN RELAY 
    1. Remove the EFI MAIN relay from the fusible link block.
    2. Measure the EFI MAIN relay resistance.

      Standard resistance 

      TESTER CONNECTION SPECIFIED CONDITION

      Tester Connection Specified Condition
      3 - 5 10 kΩ or higher
      3 - 5 Below 1 Ω (when battery voltage applied to terminals 1 and 2)
    3. Reinstall the EFI MAIN relay.
      Fig 7: Identifying EFI Main Relay Connector Terminals
      G04942983Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPLACE EFI MAIN RELAY 

    OK: Go to Next Step 

  9. CHECK HARNESS AND CONNECTOR (EFI MAIN RELAY - ECM, EFI MAIN RELAY - BODY GROUND) 
    1. Check the harness and connector between the EFI MAIN relay and ECM.
      1. Remove the EFI MAIN relay from the engine room R/B.
      2. Disconnect the E5 ECM connector.
      3. Measure the resistance between the terminals.

        Standard resistance: 

        Check for open 

        TESTER CONNECTION SPECIFIED CONDITION

        Tester Connection Specified Condition
        EFI MAIN relay terminal (1) - MREL (E5-8) Below 1 Ω

        Check for short 

        TESTER CONNECTION SPECIFIED CONDITION

        Tester Connection Specified Condition
        EFI MAIN relay terminal (1) or MREL (E5-8) - Body ground 10 kΩ or higher
    2. Check the harness and connector between the EFI MAIN relay and body ground.
      1. Measure the resistance between the terminals.

        Standard resistance : 

        Check for open 

        TESTER CONNECTION SPECIFIED CONDITION

        Tester Connection Specified Condition
        EFI MAIN relay terminal (2) - Body ground Below 1 Ω
      2. Reinstall the engine room R/B.
      3. Reconnect the ECM connector.
      Fig 8: Identifying EFI Main Relay And E5 Connectors Terminals
      G05268239Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    NG: CHECK AND REPLACE HARNESS AND CONNECTOR (TERMINAL +B OF ECM - BATTERY POSITIVE TERMINAL) 

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