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

DESCRIPTION

A004RX4E01

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

Duty Ratio:

The duty ratio is the ratio of the blower with fan motor sub-assembly ON time (T1) to the total of the blower with fan motor sub-assembly ON and OFF time (T2).

The air conditioning amplifier assembly controls the blower with fan motor sub-assembly speed.

WIRING DIAGRAM

A004OVVE09
*a from HTR Fuse
*b Air Conditioning Amplifier Assembly
*c Blower with Fan Motor Sub-assembly

PROCEDURE


  1. PERFORM ACTIVE TEST USING INTELLIGENT TESTER


    1. Select the Active Test, use the intelligent tester to generate a control command, and then check that the blower with fan motor sub-assembly operates.

      Air Conditioner
      Tester Display Test Part Control Range Diagnostic Note
      Blower Motor Blower motor speed level Min.: 0, Max.: 31 -
      OK
      Blower motor operates and blower motor speed changes.
      Result
      Result Proceed to
      OK (Blower motor operates normally) A
      NG (Blower motor does not operate) B
      NG (Blower motor operates but does not change speed) C

    A

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

    C

    CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER - BODY GROUND) Click here

    B

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


    1. A004S6HE01
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Blower with Fan Motor Sub-assembly)

      Disconnect the D29 motor connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      D29-3 (+B) - 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
      D29-1 (GND) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. CHECK HARNESS AND CONNECTOR (BLOWER MOTOR - AIR CONDITIONING AMPLIFIER)


    1. A004U3NE01
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Blower with Fan Motor Sub-assembly)
      *2

      Rear view of wire harness connector

      (to Air Conditioning Amplifier Assembly)

      Disconnect the D47 amplifier connector.

    2. Disconnect the D29 motor connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      D47-23 (BLW) - D29-2 (SI) Always Below 1 Ω
      D47-23 (BLW) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK BLOWER WITH FAN MOTOR SUB-ASSEMBLY (OPERATION)


    1. Replace the blower with fan motor sub-assembly with a new or normally functioning one Click here.

    2. Operate the blower with fan motor sub-assembly to check that it functions properly.

      OK
      Blower with fan motor sub-assembly operates normally.

    OK

    END (BLOWER WITH FAN MOTOR SUB-ASSEMBLY IS FAULTY)

    NG

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

  5. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER - BODY GROUND)

    A004RQ6E01
    Text in Illustration
    *1

    Rear view of wire harness connector

    (to Air Conditioning Amplifier Assembly)

    1. Disconnect the D47 amplifier connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      D47-14 (GND) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY (BLW SIGNAL)


    1. A004TIJE01
      Text in Illustration
      *1

      Component with harness connected

      (Air Conditioning Amplifier Assembly)

      Remove the air conditioning amplifier assembly with its connectors still connected Click here.

    2. Using an oscilloscope, check the waveform.

      Measurement Condition
      Item Content
      Terminal No. (Symbol) D47-23 (BLW) - D47-14 (GND)
      Tool Setting 1 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.


    NG

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    OK

  7. CHECK BLOWER WITH FAN MOTOR SUB-ASSEMBLY (OPERATION)


    1. Replace the blower with fan motor sub-assembly with a new or normally functioning one Click here.

    2. Operate the blower with fan motor sub-assembly to check that it functions properly.

      OK
      Blower with fan motor sub-assembly operates normally.

    OK

    END (BLOWER WITH FAN MOTOR SUB-ASSEMBLY IS FAULTY)

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR