AIR CONDITIONING SYSTEM Blower Motor Circuit

DESCRIPTION

The blower motor with fan sub-assembly reads the signal from the air conditioning amplifier assembly and controls operation and speed changes of the blower motor.

If the blower air volume is weak, or there are any other blower malfunctions such as the temperature or air volume cannot be changed, the following causes are possible.

Malfunction Status Factor

  • Blower airflow volume is weak

  • Blower airflow volume cannot be changed

  • Blower airflow volume cannot be changed

  • Air conditioning amplifier assembly malfunction

  • Blower with fan motor sub-assembly malfunction

  • Integration control and panel assembly malfunction

  • Air conditioning filter clogging

  • Evaporator or heater core fin clogging

WIRING DIAGRAM

B000S02E10
*a from Auxiliary Battery
*b Blower with Fan Motor Sub-assembly
*c Air Conditioning Amplifier Assembly

CAUTION / NOTICE / HINT

Note

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

PROCEDURE


  1. PERFORM ACTIVE TEST USING GTS (BLOWER MOTOR)


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the GTS on.

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

    5. Perform the Active Test according to the display on the GTS.


      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 is operated.
      Result
      Proceed to
      OK
      NG

    NG

    GO TO STEP 5 Click here

    OK

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


    1. B000OV4C02
      *a

      Front view of wire harness connector

      (to Blower with Fan Motor Sub-assembly)

      Disconnect the blower with fan motor sub-assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A19-1 (GND) - Body ground Always Below 1 Ω

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      A19-3 (+B) - Body ground Power switch off 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER ASSEMBLY - BLOWER WITH FAN MOTOR SUB-ASSEMBLY)


    1. Disconnect the P58 air conditioning amplifier assembly connector.

    2. Disconnect the A19 blower with fam motor sub-assemblyconnector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      P58-6 (BLW) - A19-2 (SI) Always Below 1 Ω
      P58-6 (BLW) or A19-2 (SI) - Other terminals and body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK BLOWER WITH FAN MOTOR SUB-ASSEMBLY


    1. B000QU7C05
      *a

      Front 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 Condition Specified Condition
      P58-6 (BLW) - Body ground Always 4.75 to 5.25 V
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE BLOWER WITH FAN MOTOR SUB-ASSEMBLY Click here

    OK

  5. CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY


    1. B000OTWC04
      *a

      Component with harness connected

      (Blower with Fan Motor Sub-assembly)

      Using the oscilloscope, check for the waveform.

      Item Content
      Terminal No. A19-2 (SI) - Body ground
      Tool Setting 2 V/DIV., 1 ms./DIV.
      Vehicle Condition

      • Power switch on (IG)

      • Blower switch: LO

      Tech Tips

      The waveform varies with the blower speed.

      OK
      Waveform is similar to that shown in the illustration.
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE BLOWER WITH FAN MOTOR SUB-ASSEMBLY Click here

    NG

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here