RX300 1999

Evaporative Emission Control System

Print

EVAP Canister



Operation

Specific to:

Lexus RX300 1999-2003

Lexus RX330 2004-2006

The Evaporative Emissions (EVAP) Canister is the primary component in the Evaporative Emission (EVAP) Control System that prevents the evaporation of unburned fuel vapors (Hydrocarbons) from being released into the atmosphere. The EVAP canister contains a charcoal element for the filtering of hydrocarbons, and the filtered Carbon Dioxide (CO2) is then vented to atmosphere when the vehicle is not in operation. The canister also contains a number of ports, which provide for the redistribution of hydrocarbons into the fuel tank when the vehicle is in operation through the purge control system.

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. Raise and safely support the vehicle.
  6.  
  7. Remove the canister protector retaining nuts. Remove the canister protector cover.
  8.  
  9. Disconnect the hoses from the canister.
  10.  
  11. Remove the canister retaining bolts.
  12.  
  13. Remove the canister from its mounting.

    Click image to see an enlarged view

    Fig. EVAP canister and related components-RX300

  14.  

To install:


NOTE
Be sure to use new fasteners, as required.

  1. Installation is the reverse of the removal procedure.
  2.  

Testing
Evaporative Emission Control System Diagnostics

Specific to:

Lexus RX300 1999-2003

Lexus RX330 2004-2006

When testing the EVAP system for proper operation, there should always be a pressure differential between the fuel tank pressure and atmospheric pressure. If any of the tests reveal a pressure differential of less than .02- Hg (.067 kPa/.5mm Hg), the Powertrain Control Module (PCM) will interpret this condition as a leak.

  1. Verify the condition of the EVAP system by performing the following visual inspections:

    Ensure that the fuel filler cap is installed and properly secured.
     
    Inspect the charcoal canister for physical damage such as cracks, broken or cracked fittings, damage from road debris, or rodent damage.
     
    Inspect all EVAP control devices (EVAP and purge control system monitors, controllers, and actuators) for physical damage such as cracks, broken or cracked fittings, damage from road debris, or rodent damage.
     
    Inspect all hoses and vacuum line connections for proper routing and placement.
     
    Inspect all electronic control devices for proper electrical connections.
     
    Inspect the condition of all fittings and seals for damage, drying, or wear.
     
    Inspect the condition of all hoses and vacuum lines for displacement, damage, or wear.
     

  2.  

If any physical defects are evident, verify the operation of any questionable components before replacement.

  1. Verify the operation of the EVAP system by performing any or all the following tests:

    Using a suitable scan tool, perform an actuator (active) test to verify the correct operation of EVAP control devices (EVAP and purge control system monitors, controllers, and actuators).
     
    Using a smoke machine, verify that the EVAP system does not exhibit any physical leaks.
     
    Using a suitable EVAP system pressure tester, verify that the EVAP system is properly sealed against positive and negative pressure.
     
    Using a suitable EVAP system pressure tester along with a suitable scan tool, monitor the EVAP pressure under positive and negative pressure conditions.
     

  2.  

Related Diagnostic Trouble Codes

Specific to:

Lexus RX300 1999-2003

Lexus RX330 2004-2006



Click image to see an enlarged view

Fig. Related Diagnostic Trouble Codes

Fuel Tank Vapor Pressure Sensor



Operation

Specific to:

Lexus RX300 1999-2003

Lexus RX330 2004-2006

The Fuel Tank Pressure Sensor (EVAP Pressure Sensor) is a piezoelectric (pressure-sensitive) electronic device that monitors the pressure differential between the Evaporative Emission Control (EVAP) system and atmospheric pressure. The EVAP Pressure Sensor operates within a 5 volt DC reference range, and provides a linear input signal to the Powertrain Control Module (PCM).

Removal & Installation

Specific to:

Lexus RX300 1999-2003

At this time the manufacturer does not provide removal and installation procedures for this component.

Click image to see an enlarged view

Fig. Vapor pressure sensor and related components (1 of 2)-RX300



Click image to see an enlarged view

Fig. Vapor pressure sensor and related components (2 of 2)-RX300

Testing
Connection & Wiring Diagnosis

Specific to:

Lexus RX300 1999-2003

Lexus RX330 2004-2006

Refer to the Electrical Wiring Diagram for component and connector locations, connector views, and circuit-specific information.

Many intermittent open or short circuits may be caused by wiring harness and connector movement due to vibration, engine torque, bumps and rough pavement, etc.

  1. Test the wiring harness and connectors by performing the following tests:

    Move the related connectors and wiring while monitoring the appropriate scan tool data.
     
    Move the related connectors and wiring with the component commanded ON and OFF. Using a suitable the scan tool, observe the component operation.
     
    With the engine running, move the related connectors and wiring while monitoring component operation.
     
    If harness or connector movement affects the data displayed, the component and system operation, or the engine operation, inspect and repair the harness or connections as necessary.
     

  2.  
  3. Test the connector terminal pins and/or wiring by performing the following tests:

    Inspect for incorrect mating of the connector halves, or terminals not fully seated in the connector body.
     
    Inspect for improperly formed or damaged terminals and test for incorrect terminal tension.
     
    Inspect for poor terminal to wire connections including terminals crimped over insulation. This requires removing the terminal from the connector body.
     
    Inspect for corrosion or water intrusion. Pierced or damaged insulation can allow moisture to enter the wiring. The conductor can corrode inside the insulation with little visible evidence. Look for swollen and/or brittle sections of wire in the suspect circuits.
     
    Inspect for wires that are broken inside the insulation by gently pulling on suspect sections of wiring.
     

  4.  

EVAP Pressure Sensor

Specific to:

Lexus RX300 1999-2003

Lexus RX330 2004-2006

When testing the EVAP system for proper operation, there should always be a pressure differential between the fuel tank pressure and atmospheric pressure. If any of the tests reveal a pressure differential of less than .02- Hg (.067 kPa/.5mm Hg), the Powertrain Control Module (PCM) will interpret this condition as a leak.

  1. Verify the condition of the EVAP system by performing the following visual inspections:

    Ensure that the fuel filler cap is installed and properly secured.
     
    Inspect the charcoal canister for physical damage such as cracks, broken or cracked fittings, damage from road debris, or rodent damage.
     
    Inspect all EVAP control devices (EVAP and purge control system monitors, controllers, and actuators) for physical damage such as cracks, broken or cracked fittings, damage from road debris, or rodent damage.
     
    Inspect all hoses and vacuum line connections for proper routing and placement.
     
    Inspect all electronic control devices for proper electrical connections.
     
    Inspect the condition of all fittings and seals for damage, drying, or wear.
     
    Inspect the condition of all hoses and vacuum lines for displacement, damage, or wear.
     

  2.  

If any physical defects are evident, verify the operation of any questionable components before replacement.

  1. Verify the operation of the EVAP system by performing any or all the following tests:

    Using a suitable scan tool, perform an actuator (active) test to verify the correct operation of EVAP control devices (EVAP and purge control system monitors, controllers, and actuators).
     
    Using a smoke machine, verify that the EVAP system does not exhibit any physical leaks.
     
    Using a suitable EVAP system pressure tester, verify that the EVAP system is properly sealed against positive and negative pressure.
     
    Using a suitable EVAP system pressure tester along with a suitable scan tool, monitor the EVAP pressure under positive and negative pressure conditions.
     

  2.  

Verify the operation of all EVAP system components before replacing the EVAP Pressure Sensor.

Click image to see an enlarged view

Fig. EVAP Pressure Sensor Range Chart

EVAP Pressure Sensor Strategy

Specific to:

Lexus RX300 1999-2003

Lexus RX330 2004-2006

The EVAP Pressure Sensor is the central component in the EVAP monitoring system. EVAP is a non-continuous monitor under Mode 6 OBD-II diagnostics, and operates within a 5 volt DC reference range . The Powertrain Control Module (PCM) utilizes EVAP Pressure Sensor data to monitor the fuel tank pressure differential, and will log a Diagnostic Trouble Code (DTC) in the event of any leak larger than .02- Hg (.067 kPa/.5mm Hg).

Related Diagnostic Trouble Codes (DTC)

Specific to:

Lexus RX300 1999-2003

Lexus RX330 2004-2006



Click image to see an enlarged view

Fig. Related Diagnostic Trouble Codes

 
label.common.footer.alt.autozoneLogo