AIR CONDITIONING SYSTEM(for Automatic Air Conditioning System) Blower Motor Circuit

DESCRIPTION

The blower with fan motor sub-assembly is operated by signals from the air conditioning amplifier assembly. Blower motor speed signals are transmitted in accordance with changes in the duty ratio.

WIRING DIAGRAM

B003JFHE04
*a from Battery
*b Blower Motor Control
*c Air Conditioning Amplifier Assembly
*d Blower with Fan Motor Sub-assembly

CAUTION / NOTICE / HINT

Note


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

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

    Click here

PROCEDURE


  1. PERFORM ACTIVE TEST USING GTS (BLOWER MOTOR)


    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
      Blower Motor Blower with fan motor sub-assembly

      Min.: 0

      Max.: 31

      		 -

      Body Electrical > Air Conditioner > Active Test
      Tester Display
      Blower Motor
      OK
      Blower with fan motor sub-assembly operates and changes speed.
      Result
      Proceed to
      OK
      NG

    OK

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here

    NG

  2. INSPECT BLOWER WITH FAN MOTOR SUB-ASSEMBLY


    1. Remove the blower with fan motor sub-assembly.

      Click here

    2. Inspect the blower with fan motor sub-assembly.

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE BLOWER WITH FAN MOTOR SUB-ASSEMBLY Click here

    OK

  3. CHECK HARNESS AND CONNECTOR (BLOWER MOTOR CONTROL - BATTERY AND BODY GROUND)


    1. B003QMQC04
      *a

      Front view of wire harness connector

      (to Blower Motor Control)

      Disconnect the blower motor control connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      G35-6 (GND) - Body ground Always Below 1 Ω

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      G35-1 (+B) - Body ground Always 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK HARNESS AND CONNECTOR (BLOWER MOTOR CONTROL - AIR CONDITIONING AMPLIFIER ASSEMBLY)


    1. Disconnect the G35 blower motor control 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
      G35-3 (SI) - G37-22 (BLW) Always Below 1 Ω
      G35-3 (SI) or G37-22 (BLW) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. CHECK HARNESS AND CONNECTOR (BLOWER WITH FAN MOTOR SUB-ASSEMBLY - BLOWER MOTOR CONTROL AND BODY GROUND)


    1. Disconnect the G6 blower with fan motor sub-assembly connector.

    2. Disconnect the G35 blower motor control connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      G6-2 (B) - G35-2 (VM) Always Below 1 Ω
      G6-1 (L) - Body ground Always Below 1 Ω
      G6-2 (B) or G35-2 (VM) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY


    1. B003QFSC03
      *a

      Component with harness connected

      (Blower Motor Control)

      Using an oscilloscope, check the waveform.

      Item Content
      Terminal No. (Symbol) G35-3 (SI) - Body ground
      Tool Setting 2 V/DIV., 500 μs/DIV.
      Condition

      • Ignition switch ON

      • Blower switch: LO
      OK
      Waveform is as shown in the illustration.

      Tech Tips

      Waveform varies with the blower level.

      Result
      Proceed to
      OK
      NG

    OK

    REPLACE BLOWER MOTOR CONTROL Click here

    NG

  7. CHECK BLOWER MOTOR CONTROL


    1. Replace the blower motor control.

      Click here

    2. Check if the same malfunction recurs when the sonar function is operated.

      OK
      Malfunction does not reoccur (returns to normal).
      Result
      Proceed to
      OK
      NG

    OK

    END (BLOWER MOTOR CONTROL IS DEFECTIVE)

    NG

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here