HEATED WINDSHIELD DEFROSTER SYSTEM Heated Windshield Defroster System does not operate

DESCRIPTION

When the No. 2 combination switch assembly (windshield deicer switch) is operated, the operation signal is transmitted to the air conditioning amplifier assembly directly. When the air conditioning amplifier assembly receives the signal, it turns on the EHW NO. 1 relay and EHW NO. 2 relay to operate the heated windshield defroster system.

WIRING DIAGRAM

B0059MVE01

CAUTION / NOTICE / HINT

Note


  • Inspect the fuses for circuits related to this system before performing the following procedure.

  • If the battery voltage is low, the heated windshield defroster system may not operate. Refer to Data List for the power steering system.

    for Power Tilt and Power Telescopic Steering Column: Click here

    for Manual Tilt and Manual Telescopic Steering Column: Click here

  • The heated windshield defroster system uses the CAN communication system. First, confirm that there are no malfunctions in the communication system by checking the communication function of the CAN communication system. Refer to the How to Proceed with Troubleshooting procedure

    Click here

  • If the ambient temperature is 5°C (41°F) or higher, or if a malfunction of the ambient temperature sensor (thermistor assembly) is detected, the EHW NO. 1 relay and EHW NO. 2 relay will be deactivated and the No. 2 combination switch assembly (windshield deicer switch) indicator light will blink.

PROCEDURE


  1. CHECK FOR DTC


    1. Clear the DTCs.

      Click here


      Body Electrical > Air Conditioner > Clear DTCs

    2. Recheck for DTCs.

      Click here


      Body Electrical > Air Conditioner > Trouble Codes
      Result
      Result Proceed to
      DTC B1412 is output A
      DTC B1412 is not output B

    A

    GO TO AIR CONDITIONING SYSTEM (B1412) Click here

    B

  2. PERFORM ACTIVE TEST USING GTS


    1. Connect the GTS to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the GTS on.

    4. Enter the following menus: Body Electrical / Air Conditioner / Active Test.

    5. 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
      HWD Relay Windshield glass (heated windshield defroster) OFF or ON -

      Body Electrical > Air Conditioner > Active Test
      Tester Display
      HWD Relay
      OK
      The heated windshield defroster system operates normally.
      Result
      Result Proceed to
      OK A
      NG (Neither heated windshield defroster LH nor heated windshield defroster RH does not warm up.) B
      NG (Only heated windshield defroster LH does not warm up.) C
      NG (Only heated windshield defroster RH does not warm up.) D

    B

    INSPECT EHW NO. 1 RELAY Click here

    C

    CHECK HARNESS AND CONNECTOR (WINDSHIELD GLASS (HEATED WINDSHIELD DEFROSTER LH) - EHW NO. 1 RELAY AND BODY GROUND) Click here

    D

    INSPECT EHW NO. 2 RELAY Click here

    A

  3. INSPECT NO. 2 COMBINATION SWITCH ASSEMBLY (WINDSHIELD DEICER SWITCH)


    1. Remove the No. 2 combination switch assembly (windshield deicer switch).

      Click here

    2. Inspect the No. 2 combination switch assembly (windshield deicer switch).

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE NO. 2 COMBINATION SWITCH ASSEMBLY (WINDSHIELD DEICER SWITCH) Click here

    OK

  4. CHECK HARNESS AND CONNECTOR (NO. 2 COMBINATION SWITCH ASSEMBLY (WINDSHIELD DEICER SWITCH) - BATTERY)


    1. B0057R1C01
      *a

      Front view of wire harness connector

      (to No. 2 Combination Switch Assembly (Windshield Deicer Switch))

      Disconnect the No. 2 combination switch assembly (windshield deicer switch) connector.

    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      I37-7 (IG) - Body ground Engine switch off Below 1 V
      Engine switch on (IG) 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. CHECK HARNESS AND CONNECTOR (NO. 2 COMBINATION SWITCH ASSEMBLY (WINDSHIELD DEICER SWITCH) - AIR CONDITIONING AMPLIFIER ASSEMBLY)


    1. Disconnect the I37 No. 2 combination switch assembly (windshield deicer switch) connector.

    2. Disconnect the I50 and I54 air conditioning amplifier assembly connectors.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      I37-20 (D) - I50-23 (IND) Always Below 1 Ω
      I37-20 (D) or I50-23 (IND) - Body ground Always 10 kΩ or higher
      I37-19 (E) - I54-21 (DFAC) Always Below 1 Ω
      I37-19 (E) or I54-21 (DFAC) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  6. INSPECT EHW NO. 1 RELAY


    1. Remove the EHW NO. 1 relay from the No. 2 engine room relay block assembly.

    2. Inspect the EHW NO. 1 relay.

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE EHW NO. 1 RELAY

    OK

  7. CHECK HARNESS AND CONNECTOR (EHW NO. 1 RELAY - BATTERY)


    1. Remove the EHW NO. 1 relay from the No. 2 engine room relay block assembly.

    2. B0058EIC04
      *a

      Front view of wire harness connector

      (to EHW NO. 1 Relay)

      Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Condition Specified Condition
      EHW NO. 1 relay holder terminal-2 - Body ground Engine switch on (IG) 11 to 14 V
      EHW NO. 1 relay holder terminal-3 - Body ground Always 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  8. CHECK HARNESS AND CONNECTOR (EHW NO. 1 RELAY - AIR CONDITIONING AMPLIFIER ASSEMBLY)


    1. Remove the EHW NO. 1 relay from the No. 2 engine room relay block assembly.

    2. Disconnect the I50 air conditioning amplifier assembly connector.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      EHW NO. 1 relay holder terminal-1 - I50-39 (FDEF) Always Below 1 Ω
      EHW NO. 1 relay holder terminal-1 or I50-39 (FDEF) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  9. CHECK HARNESS AND CONNECTOR (EHW NO. 1 RELAY - EHW NO. 2 RELAY OR WINDSHIELD GLASS (HEATED WINDSHIELD DEFROSTER LH))


    1. Remove the EHW NO. 1 relay and EHW NO. 2 relay from the No. 2 engine room relay block assembly.

    2. Disconnect the A72 windshield glass (heated windshield defroster LH) connector.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      EHW NO. 1 relay holder terminal-5 - EHW NO. 2 relay holder terminal-2 Always Below 1 Ω
      EHW NO. 1 relay holder terminal-5 - A72-1 (B) Always Below 1 Ω
      EHW NO. 1 relay holder terminal-5 - Body ground Always 10 kΩ or higher
      EHW NO. 2 relay holder terminal-2 - Body ground Always 10 kΩ or higher
      A72-1 (B) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  10. CHECK HARNESS AND CONNECTOR (WINDSHIELD GLASS (HEATED WINDSHIELD DEFROSTER LH) - EHW NO. 1 RELAY AND BODY GROUND)


    1. Disconnect the A72 windshield glass (heated windshield defroster LH) connector.

    2. Remove the EHW NO. 1 relay from the No. 2 engine room relay block assembly.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      A72-1 (B) - EHW NO. 1 relay holder terminal-5 Always Below 1 Ω
      A72-2 (E) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE WINDSHIELD GLASS (HEATED WINDSHIELD DEFROSTER LH) Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  11. INSPECT EHW NO. 2 RELAY


    1. Remove the EHW NO. 2 relay from the No. 2 engine room relay block assembly.

    2. Inspect the EHW NO. 2 relay.

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE EHW NO. 2 RELAY

    OK

  12. CHECK HARNESS AND CONNECTOR (EHW NO. 2 RELAY - BATTERY AND BODY GROUND)


    1. Remove the EHW NO. 2 relay from the No. 2 engine room relay block assembly.

    2. B0058EIC04
      *a

      Front view of wire harness connector

      (to EHW NO. 2 Relay)

      Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Condition Specified Condition
      EHW NO. 2 relay holder terminal-3 - Body ground Always 11 to 14 V

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      EHW NO. 2 relay holder terminal-1 - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  13. CHECK HARNESS AND CONNECTOR (EHW NO. 2 RELAY - EHW NO. 1 RELAY)


    1. Remove the EHW NO. 1 relay and EHW NO. 2 relay from the No. 2 engine room relay block assembly.

    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      EHW NO. 2 relay holder terminal-2 - EHW NO. 1 relay holder terminal-5 Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  14. CHECK HARNESS AND CONNECTOR (WINDSHIELD GLASS (HEATED WINDSHIELD DEFROSTER RH) - EHW NO. 2 RELAY AND BODY GROUND)


    1. Disconnect the A71 windshield glass (heated windshield defroster RH) connector.

    2. Remove the EHW NO. 2 relay from the No. 2 engine room relay block assembly.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      A71-1 (B) - EHW NO. 2 relay holder terminal-5 Always Below 1 Ω
      A71-2 (E) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE WINDSHIELD GLASS (HEATED WINDSHIELD DEFROSTER RH) Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR