DSD Information System
Home >> Toyota >> 2021 >> Highlander LE, 4WD >> Repair and Diagnosis >> Accessories & Equipment >> Heated Glass/Defoggers >> Windshield Deicer System - Diagnostics & Symptom Tests >> Windshield Deicer System >> Windshield Deicer does not Operate [11/2023 - ] >> Procedure

Windshield Deicer does not Operate [11/2023 - ]: Procedure

  1. CHECK AIR CONDITIONING SYSTEM 
    1. Check air conditioning system.

      For HV Model: Refer to HOW TO PROCEED WITH TROUBLESHOOTING [11/2023 - ]

      For Gasoline Model: Refer to HOW TO PROCEED WITH TROUBLESHOOTING [11/2023 - ]

      HINT: 

      Both the windshield deicer system operation signal and air conditioning system operation signal are transmitted to the air conditioning amplifier assembly through same communication line.

      OK

      The air conditioning system operates normally.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    GO TO AIR CONDITIONING SYSTEM 

    For HV Model: Refer to HOW TO PROCEED WITH TROUBLESHOOTING [11/2023 - ]

    For Gasoline Model: Refer to HOW TO PROCEED WITH TROUBLESHOOTING [11/2023 - ]

    Result: 

    OK 

    See step  2

  2. PERFORM ACTIVE TEST USING GTS 
    1. Perform the Active Test according to the display on the GTS.

      Body Electrical > Air Conditioner > Active Test 

      Tester Display Measurement Item Control Range Diagnostic Note
      Front Deicer Relay Windshield deicer wire OFF or ON -

      Body Electrical > Air Conditioner > Active Test 

      Tester Display
      Front Deicer Relay

      OK

      The windshield deicer system operates normally.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  4

    Result: 

    OK 

    See step  3

  3. CHECK AIR CONDITIONING CONTROL ASSEMBLY 
    1. Replace the air conditioning control assembly with a new or known good one.

      Refer to REMOVAL [10/2022 - ]

    2. Check that the windshield deicer system operates normally.

      OK

      The windshield deicer system operates normally.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    END (AIR CONDITIONING CONTROL ASSEMBLY IS DEFECTIVE) 

    Result: 

    NG 

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY 

    Refer to REMOVAL [11/2023 - ]

  4. INSPECT DEICER RELAY 
    1. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      3 - 5 Auxiliary battery voltage applied between terminals 1 and 2 Below 1 Ω
      3 - 5 Auxiliary battery voltage not applied between terminals 10 kΩ or higher
      GTY329933Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPLACE DEICER RELAY 

    Result: 

    OK 

    See step  5

  5. CHECK WIRE HARNESS AND CONNECTOR (DEICER RELAY - POWER SUPPLY) 
    1. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      DEICER relay holder terminal 2 - Body ground Ignition switch ON 11 to 14 V
      DEICER relay holder terminal 3 - Body ground Ignition switch off 11 to 14 V

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  6

  6. CHECK WIRE HARNESS AND CONNECTOR (DEICER RELAY - AIR CONDITIONING AMPLIFIER ASSEMBLY) 
    1. Disconnect the H62 air conditioning amplifier assembly connector.
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      DEICER relay holder terminal 1 - H62-22 (FDEF) Always Below 1 Ω
      DEICER relay holder terminal 1 or H62-22 (FDEF) - Body ground Always 10 kΩ higher

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  7

  7. CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY 
    1. Connect the H62 air conditioning amplifier assembly connector.
    2. Measure the voltage according to the value(s) in the table below.
      GTY1179422Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Component with harness connected
      (Air Conditioning Amplifier Assembly)

      Standard Voltage

      Tester Connection Condition Specified Condition
      H62-22 (FDEF) - H62-17 (GND) Ignition switch ON, windshield deicer switch on Below 2.2 V
      H62-22 (FDEF) - H62-17 (GND) Ignition switch ON, windshield deicer switch off 11 to 14 V

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY 

    Refer to REMOVAL [11/2023 - ]

    Result: 

    OK 

    See step  8

  8. CHECK WIRE HARNESS AND CONNECTOR (WINDSHIELD GLASS (WINDSHIELD DEICER WIRE) - DEICER RELAY AND BODY GROUND) 
    1. Disconnect the A60 windshield glass (windshield deicer wire) connector.
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      A60-1 (B) - DEICER relay holder terminal 5 Always Below 1 Ω
      A60-3 (B2) - DEICER relay holder terminal 5 Always Below 1 Ω
      A60-1 (B) or DEICER relay holder terminal 5 - Body ground Always 10 kΩ higher
      A60-3 (B2) or DEICER relay holder terminal 5 - Body ground Always 10 kΩ higher
      A60-2 (E) - Body ground Always Below 1 Ω

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE WINDSHIELD GLASS (WINDSHIELD DEICER WIRE) 

    Refer to REMOVAL [11/2023 - ]

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

Diesel-Data.com