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

B001AHUE01

PROCEDURE


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


    1. Use the Data List to check if the heater switch assembly is functioning properly Click here.

      Air Conditioner
      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

      		 -
      OK
      The display is as specified in the normal condition column.

    NG

    CHECK HARNESS AND CONNECTOR (IDLE UP SWITCH - BATTERY AND BODY GROUND) Click here

    OK

  2. PERFORM ACTIVE TEST USING GTS (VISCOUS HEATER)


    1. Select the Active Test, use the GTS to generate a control command, and then check that the viscous heater relay (VICS HTR) Click here.

      Tester Display Test Part Control Range Diagnostic Note
      Viscous Heater Viscous heater relay ON / OFF -
      OK
      Viscous heater relay operates using GTS.

    OK

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    NG

    CHECK VISCOUS HEATER RELAY (VICS HTR RELAY) Click here

  3. CHECK HARNESS AND CONNECTOR (IDLE UP SWITCH - BATTERY AND BODY GROUND)


    1. B00191GE01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to heater switch assembly)

      Disconnect the heater switch assembly assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      E172-3 (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
      E172-2 (IND+) - Body ground Engine switch off Below 1 V
      E172-2 (IND+) - Body ground Engine switch on (IG) 11 to 14 V

    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.


    NG

    REPLACE HEATER SWITCH ASSEMBLY Click here

    OK

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


    1. Disconnect the E35 air conditioning amplifier assembly connector.

    2. Disconnect the E172 heater switch assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      E35-28 (SW 1) - E172-6 (+S) Always Below 1 Ω
      E35-28 (SW 1) or E172-6 (+S) - Body ground Always 10 kΩ or higher

    OK

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  6. CHECK VISCOUS HEATER RELAY (VICS HTR RELAY)


    1. Replace the the No. 1 engine room relay block (viscous heater relay [VICS HTR]).

    2. Check that the air conditioning system is operated normally.

      OK
      Air conditioning system is operated normally.

    OK

    END (NO.1 ENGINE ROOM RELAY BLOCK WAS DEFECTIVE)

    NG

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


    1. B001AS9E01
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to Air Conditioning Amplifier Assembly)

      Disconnect the air conditioning amplifier assembly connector.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      E36-32 (MGCA) - Body ground Engine switch off Below 1 V
      E36-32 (MGCA) - Body ground Engine switch on (IG) 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. Disconnect the 1O, 1M No. 1 engine room relay block connector.

    2. Disconnect the C103 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
      1O-2 - C103- (MG+) Always Below 1 Ω
      1O-2 or C103- (MG+ - Body ground Always 10 kΩ or higher

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

        Standard Voltage
        Tester Connection Condition Specified Condition
        1M-1 - Body ground Always 11 to 14 V
        1O-3 - Body ground Engine switch off Below 1 V
        1O-3 - Body ground Engine switch on (IG) 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  9. CHECK VISCOUS WITH MAGNET CLUTCH HEATER ASSEMBLY


    1. Replace the viscous with magnet clutch heater assembly with a new or known good one Click here.

    2. Check that the air conditioning system is operated normally.

      OK
      Air conditioning system is operated normally.

    OK

    END (VISCOUS WITH MAGNET CLUTCH HEATER ASSEMBLY WAS DEFECTIVE)

    NG

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here