Window Defogger System: Inspection

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: Inspecting Air Conditioning Control (Auto Air Conditioning)

   Courtesy 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: Disconnecting Connector From A/C Control Assy

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Standard: 

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

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: Inspecting Air Conditioning Control Assembly (Auto Air Conditioning

   Courtesy 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 4: Disconnecting Connector From A/C Control Assembly

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Standard: 

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

1. Inspect operation of the mirror heater.

Standard: 

Fig 5: Inspecting Outer Rear View Mirror LH (W/ Outer Mirror Heater)

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

1. Inspect operation of the mirror heater.

   Standard: 

   TERMINAL SPECIFICATION
   
   

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

   Fig 6: Inspecting Outer Rear View Mirror Rh (W/ Outer Mirror Heater)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

1. Inspect operation of the defogger switch illumination.

   Standard: 

   TERMINAL SPECIFICATION
   
   

   Measurement Condition	Specified Condition
   Battery positive (+) --> ILL+ (1) 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 Outer Mirror Heater Switch (W/ Outer Mirror Heater)

   Courtesy 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: Inspecting Operation Of Defogger Timer

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Fig 9: Inspecting Back Window (Defogger Wire)

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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 the illustration.

   Standard: 

   TERMINAL SPECIFICATION
   
   

   Voltage	Criteria
   Approx. 5 V	Okay, wire is not broken
   Approx. 10 V or 0 V	Wire is broken

   Fig 10: Inspecting Voltage At Center Of Each Heat Wire

   Courtesy 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 deflects from several V to 0 V is the place where the defogger wire is broken.
   Fig 11: Identifying Special Tool

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   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.

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: Identifying Place Masking Tape Along Both Sides Of Wire

      Courtesy 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.
   Fig 13: Applying A Small Amount Of Agent To Wire

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Inspect the continuity.

Standard: 

If the result is not as specified, replace the relay.

Fig 14: Inspecting Defogger Relay

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1. Inspect the continuity.

Standard: 

Fig 15: Identifying Switch Memory Switch

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If the result is not as specified, replace the relay.