RX300 1999

Idle Air Control Valve

Print

Removal & Installation



Specific to:

Lexus RX300 1999-2003

  1. Before servicing the vehicle, refer to the Precautions Section.
    NOTE
    If working near and/or around the SRS system and components, be sure to disable the SRS system.

  2.  
  3. Disconnect the negative battery cable.
    NOTE
    When disconnecting the cable be sure that the ignition switch and headlight switches are off.


    NOTE
    When disconnecting the cable, certain systems will have to be initialized after reconnecting the cable. These systems are adaptive front lighting system, power window control system, power back door system, SRS system, audio system, sliding roof system and certain DTC codes. Be sure to write down any important information before disconnecting the cable. The Toyota scan tool, or equivalent, must be used. Follow the directions on the appropriate scan tool to complete initialization procedure.

  4.  
  5. Remove the throttle body.

    Click image to see an enlarged view

    Fig. Throttle body and related components (2 of 2)-RX300



    Click image to see an enlarged view

    Fig. Throttle body and related components (1 of 2)-RX300



    Click image to see an enlarged view

    Fig. IAC valve retaining screws-RX300

  6.  
  7. Remove the valve retaining screws.
  8.  
  9. Remove the valve from its mounting. Discard the gasket.
  10.  

To install:


NOTE
Be sure to use new fasteners, as required.

  1. Using a new gasket, position the valve to its mounting.
  2.  
  3. Continue the installation in the reverse order of the removal procedure.
  4.  

Testing



Specific to:

Lexus RX300 1999-2003

  1. Connect the positive (+) lead from the battery to terminal +B and negative (-) lead to terminal RSC, and check that the valve is closed.
  2.  
  3. Connect the positive (+) lead from the battery to terminal +B and negative (-) lead to terminal RSO, and check that the valve is open.
  4.  
  5. If operation is not as specified, replace the IAC valve.

    Click image to see an enlarged view

    Fig. IAC valve testing

  6.  

Specific to:

Lexus RX300 1999-2003


NOTE
Be sure that the engine is at normal operating temperature, idle speed is within specification, transmission is in N or P and the air conditioning switch is off. fore

  1. Using the Toyota scan tool, or equivalent, disconnect terminals T1 and E1 of the DLC.
  2.  
  3. Keep the engine speed at about 1000 rpm for about five seconds. Check that it returns to idle speed.
  4.  
  5. If not check the IAC valve wiring at the ECM. Correct as required.
  6.  
  7. Remove the tool from the DLC.
  8.  
  9. Remove the valve.
  10.  
  11. Check that it is half opened.
  12.  
  13. Connect the valve connector to the valve.

    Click image to see an enlarged view

    Fig. IAC valve positioning-RX300

  14.  
  15. Turn the ignition switch to the ON position.
  16.  
  17. Check that the valve moves in .5 seconds by order of fully closed, fully open and half open.
  18.  
  19. If the valve does not perform as outlined, replace it.
  20.  

 
label.common.footer.alt.autozoneLogo