AIR CONDITIONING SYSTEM(for Automatic Air Conditioning System) Viscous Heater with Magnet Clutch Circuit

DESCRIPTION

When the heater switch assembly is pushed, the air conditioning amplifier assembly turns on the viscous heater relay and operates the viscous heater. If the viscous heater does not operate when the heater switch assembly is pushed, there may be a problem in the circuit shown below.

WIRING DIAGRAM

B003SG4E07

CAUTION / NOTICE / HINT

Note

When the servo motor or air conditioning amplifier assembly is replaced, be sure to perform servo motor initialization.

Click here

Tech Tips

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

PROCEDURE


  1. READ VALUE USING GTS (IDLE UP/PWR HEAT SWITCH)


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Enter the following menus: Body Electrical / Air Conditioner / Data List.

    5. Check the value(s) by referring to the table below.


      Body Electrical > Air Conditioner > Data List
      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      IDLE UP/PWR HEAT Switch Heater switch assembly ON or OFF

      ON: Heater switch assembly on

      OFF: Heater switch assembly off

      		 -

      Body Electrical > Air Conditioner > Data List
      Tester Display
      IDLE UP/PWR HEAT Switch
      OK
      The display is as specified in the normal condition column.
      Result
      Proceed to
      OK
      NG

    NG

    CHECK HARNESS AND CONNECTOR (HEATER SWITCH ASSEMBLY - BATTERY AND BODY GROUND) Click here

    OK

  2. PERFORM ACTIVE TEST USING GTS


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

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

    5. Check the operation by referring to the table below.


      Body Electrical > Air Conditioner > Active Test
      Tester Display Measurement Item Control Range Diagnostic Note
      Viscous Heater Viscous heater relay ON/OFF -

      Body Electrical > Air Conditioner > Active Test
      Tester Display
      Viscous Heater
      OK
      Viscous heater relay operates.
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    NG

    INSPECT VISCOUS HEATER RELAY (VISCOUS) Click here

  3. CHECK HARNESS AND CONNECTOR (HEATER SWITCH ASSEMBLY - BATTERY AND BODY GROUND)


    1. B003RZOC03
      *a

      Front view of wire harness connector

      (to Heater Switch Assembly)

      Disconnect the heater switch assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      G178-5 (E) - Body ground Always Below 1 Ω

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      G178-4 (IG) - Body ground Ignition switch off Below 1 V
      Ignition switch ON 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. INSPECT HEATER SWITCH ASSEMBLY


    1. Remove the heater switch assembly.

      Click here

    2. Inspect the heater switch assembly.

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE HEATER SWITCH ASSEMBLY Click here

    OK

  5. CHECK HARNESS AND CONNECTOR (HEATER SWITCH ASSEMBLY - AIR CONDITIONING AMPLIFIER ASSEMBLY)


    1. Disconnect the G178 heater switch assembly connector

    2. Disconnect the G37 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
      G178-1 (IN) - G37-4 (SWVC) Always Below 1 Ω
      G178-1 (IN) or G37-4 (SWVC) - 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 VISCOUS HEATER RELAY (VISCOUS)


    1. Remove the viscous heater relay (VISCOUS) from the No. 5 instrument panel relay block.

    2. Inspect the viscous heater relay (VISCOUS).

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE VISCOUS HEATER RELAY

    OK

  7. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER - BATTERY)


    1. Disconnect the air conditioning amplifier assembly connector.

    2. B003MNPC55
      *a

      Rear view of wire harness connector

      (to Air Conditioning Amplifier Assembly)

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      G37-19 (MG+) - Body ground Ignition switch off Below 1 V
      G37-19 (MG+) - Body ground Ignition switch ON 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  8. INSPECT VISCOUS WITH MAGNET CLUTCH HEATER ASSEMBLY


    1. Remove the viscous with magnet clutch heater assembly.

      Click here

    2. Inspect the viscous with magnet clutch heater assembly.

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE VISCOUS WITH MAGNET CLUTCH HEATER ASSEMBLY Click here

    OK

  9. CHECK HARNESS AND CONNECTOR (VISCOUS RELAY - VISCOUS WITH MAGNET CLUTCH HEATER ASSEMBLY AND BATTERY)


    1. Remove the viscous heater relay (VISCOUS) from the No. 5 instrument panel relay block.

    2. Disconnect the C208 viscous with magnet clutch heater assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      Relay terminal 3 - C208-1 (MG+) Always Below 1 Ω
      Relay terminal 3 or C208-1 (MG+) - Body ground Always 10 kΩ or higher

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      Relay terminal 2 - Body ground Ignition switch off Below 1 V
      Relay terminal 2 - Body ground Ignition switch ON 11 to 14 V
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR