2005 Lexus GX 470FACTORY OEM SERVICE PROCEDURE

Window Defogger System: Inspection

  1. INSPECT AIR CONDITIONING CONTROL ASSY (AUTO AIR CONDITIONING) 
    1. Inspect operation of the defogger timer.
      1. Connect the positive (+) lead from the battery to terminal A3-3 and the negative (-) lead to terminal A4-6.
      2. Connect the positive (+) lead from the battery to terminal A4-1 through a 1.4 W test bulb.
      3. Push the defogger switch ON, check that the indicator light on the switch and the test bulb light up for 12 to 18 minutes, and then the indicator light and the test bulb go off.

        If the result is not as specified, replace the A/C control assy.

        Fig 1: Connecting Positive (+) Lead From Battery To Terminal A3-3 & Negative (-) Lead To Terminal A4-6
        G02963228Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Disconnect the connector from the A/C control assy.
    3. Check the voltage or continuity of each terminal of the wire harness side connector.
      Fig 2: Checking Voltage Or Continuity Of Terminal Of Wire Harness Side Connector
      G02963229Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard: 

      TERMINAL CONDITION SPECIFIED CONDITION

      Terminal No. Condition Specified Condition
      A4-6 <=> Body ground Constant Continuity
      A4-1 <=> Body ground Ignition switch Lock or ACC No voltage
      A4-1 <=> Body ground Ignition switch ON Battery positive voltage
      A3-3 <=> Body ground Ignition switch Lock or ACC No voltage
      A3-3 <=> Body ground Ignition switch ON Battery positive voltage

      If the result is not as specified, there may be a malfunction on the wire harness side.

  2. INSPECT AIR CONDITIONING CONTROL ASSY (AUTO AIR CONDITIONING, W/ EMV & NAVIGATION SYSTEM) 
    1. Inspect operation of the defogger timer.
      1. Connect the positive (+) lead from the battery to terminal 9 and the negative (-) lead to terminal 10.
      2. Connect the positive (+) lead from the battery to terminal 7 through a 1.4 W test bulb.
      3. Push the defogger switch ON, check that the indicator light on the switch and the test bulb light up for 12 to 18 minutes, and then the indicator light and the test bulb go off.

        If the result is not as specified, replace the A/C control assy.

        Fig 3: Connecting Positive (+) Lead From Battery To Terminal 9 & Negative (-) Lead To Terminal 10
        G02963230Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Disconnect the connector from the A/C control assy.
    3. Check the voltage or continuity of each terminal of the wire harness side connector.

      Standard: 

      TERMINAL CONDITION SPECIFIED CONDITION

      Terminal No. Condition Specified Condition
      10 <=> Body ground Constant Continuity
      7 <=> Body ground Ignition switch Lock or ACC No voltage
      7 <=> Body ground Ignition switch ON Battery positive voltage
      9 <=> Body ground Ignition switch Lock or ACC No voltage
      9 <=> Body ground Ignition switch ON Battery positive voltage
      Fig 4: Checking Voltage Or Continuity Of Terminal Of Wire Harness Side Connector
      G02963231Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      If the result is not as specified, there may be a malfunction on the wire harness side.

  3. INSPECT OUTER REAR VIEW MIRROR ASSY LH (W/ OUTER MIRROR HEATER) 
    1. Inspect operation of the mirror heater.

      Standard: 

      TERMINAL CONDITION SPECIFIED CONDITION

      Measurement Condition Specified Condition
      Battery positive (+) --> H+ (5) Mirror becomes warm
      Battery negative (-) --> H- (12) Mirror becomes warm

      If the result is not as specified, replace the mirror assy.

      Fig 5: Inspecting Operation Of Mirror Heater (1 Of 2)
      G02963232Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  4. INSPECT OUTER REAR VIEW MIRROR ASSY RH (W/ OUTER MIRROR HEATER) 
    1. Inspect operation of the mirror heater.

      Standard: 

      MEASUREMENT CONDITION TABLE

      Measurement Condition Specified Condition
      Battery positive (+) --> H+ (5) Mirror becomes warm
      Battery negative (-) --> H- (12) Mirror becomes warm

      If the result is not as specified, replace the mirror assy.

      Fig 6: Inspecting Operation Of Mirror Heater (2 Of 2)
      G02963233Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  5. INSPECT OUTER MIRROR HEATER SWITCH ASSY (W/ OUTER MIRROR HEATER) 
    1. Inspect operation of the defogger switch illumination.

      Standard: 

      MEASUREMENT CONDITION TABLE

      Measurement Condition Specified Condition
      Battery positive (+) --> ILL+ (1) Illumination light lights up
      Battery negative (-) --> ILL- (2) Illumination light lights up

      If the result is not as specified, replace the outer mirror heater switch assy or bulb.

      Fig 7: Inspecting Operation Of Defogger Switch Illumination
      G02963234Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Inspect operation of the defogger timer.
      1. Connect the positive (+) lead from the battery to terminal 4 and the negative (-) lead to terminal 3.
      2. Connect the positive (+) lead from the battery to terminal 5 through a 1.4 W test bulb.
      3. Push the outer mirror heater switch ON, check that the indicator light on the switch and the test bulb light up for 5 minutes, and then the indicator light and the test bulb go off.

        If the result is not as specified, replace the outer mirror heater switch assy.

        Fig 8: Connecting Positive (+) Lead From Battery To Terminal 4 & Negative (-) Lead To Terminal 3
        G02963235Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  6. INSPECT BACK WINDOW (DEFOGGER WIRE) 
    NOTE:
    • When cleaning the glass, wipe the glass along the wire using a soft and dry cloth. Take care not to damage the wires.
    • Do not use detergents or glass cleaners including abrasive ingredients.
    • When measuring voltage, wrap a piece of tin foil around the tip of the negative probe and press the foil against the wire with your finger, as shown in Fig 9.
      Fig 9: Wrapping Piece Of Tin Foil Around Tip Of Negative Probe & Press Foil Against Wire To Measure Voltage
      G02963236Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Turn the ignition switch ON.
    2. Turn the defogger switch ON.
    3. Inspect the voltage at the center of each heat wire, as shown in Fig 10.

      Standard: 

      VOLTAGE CRITERIA TABLE

      Voltage Criteria
      Approx. 5 V OK, wire is not broken
      Approx. 10 V or 0 V Wire is broken
      Fig 10: Inspecting Voltage At Center Of Each Heat Wire
      G02963237Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      HINT:

      If there is approximately 10 V, the wire may be broken between the center of the wire and the positive (+) end. If there is no voltage, the wire may be broken between the center of the wire and the ground.

    4. Place the voltmeter positive (+) lead against the defogger wire on the battery side.
    5. Place the voltmeter negative (-) lead with the foil strip against the wire on the ground side.
    6. Slide the positive (+) lead from the battery side to the ground side.
    7. The point where the voltmeter drops from several volts to 0 V is the place where the defogger wire is broken.

      HINT:

      If the defogger wire is not broken, the voltmeter indicates 0 V at the positive (+) end of the defogger wire but gradually increases to about 12 V as the meter probe moves to the other end.

      Fig 11: Placing Voltmeter Negative (-) Lead With Foil Strip Against Wire On Ground
      G02963238Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    8. If necessary, repair the defogger wire.
      1. Clean the broken wire tips with grease, wax and silicone remover.
      2. Place the masking tape along the both sides of the wire.
      3. Thoroughly mix the repair agent (DuPont paste No. 4817).
        Fig 12: Placing Masking Tape Along Both Sides Of Wire
        G02963239Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      4. Using a fine tip brush, apply a small amount of the agent to the wire.
      5. After a few minutes, remove the masking tape.
        NOTE: Do not repair the defogger wire for at least 24 hours.
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