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

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DTC Code DTC Name
  Blower Motor Circuit
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DESCRIPTION

The blower with fan motor sub-assembly operates according to 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.

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WIRING DIAGRAM

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INSPECTION PROCEDURE

Note:

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

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PROCEDURE


  1. Click here

    PERFORM ACTIVE TEST USING INTELLIGENT TESTER (BLOWER MOTOR)


    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 (Click here).

      Table 1. Air Conditioner
      Tester Display Test Part Control Range Diagnostic Note
      Blower Motor Blower with fan motor sub-assembly Min.: 0, Max.: 31 -
      OK
      Blower with fan motor sub-assembly operates and blower with fan motor sub-assembly speed changes.

  2. Click here

    CHECK HARNESS AND CONNECTOR (BLOWER WITH FAN MOTOR - BATTERY AND BODY GROUND)


    1. A0157POE23

      Disconnect the A29 blower with fan motor sub-assembly connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A29-3 (+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
      A29-1 (GND) - Body ground Always Below 1 Ω
      Table 2. Text in Illustration
      *a

      Front view of wire harness connector

      (to Blower with Fan Motor Sub-assembly)

  3. Click here

    CHECK HARNESS AND CONNECTOR (BLOWER WITH FAN MOTOR - AIR CONDITIONING AMPLIFIER)


    1. Disconnect the E81 air conditioning amplifier assembly connector.

    2. Disconnect the A29 blower with fan motor sub-assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      E81-23 (BLW) - A29-2 (SI) Always Below 1 Ω
      E81-23 (BLW) - Body ground Always 10 kΩ or higher
      E81-14 (GND) - Body ground Always Below 1 Ω

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    CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY


    1. A015AB5E05

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

    2. Using an oscilloscope, check the waveform.

      Table 3. Measurement Condition
      Item Content
      Terminal No. (Symbol) E81-23 (BLW) - E81-14 (GND)
      Tool Setting 1 V/DIV., 500 μs/DIV.
      Condition

      Ignition switch ON

      Blower switch LO level
      OK
      Waveform is as shown in the illustration.
      Table 4. Text in Illustration
      *a

      Component with harness connected

      (Air Conditioning Amplifier Assembly)
      Tip:

      Waveform varies with the blower level.


  5. Click here

    REPLACE BLOWER WITH FAN MOTOR SUB-ASSEMBLY


    1. Temporarily replace the blower with fan motor sub-assembly with a new or normally functioning one (Click here).


  6. Click here

    CHECK BLOWER WITH FAN MOTOR SUB-ASSEMBLY


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

      OK
      Blower with fan motor sub-assembly operates normally.

  7. Click here

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLEClick here

  8. Click here

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  9. Click here

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

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    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLYClick here