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

DESCRIPTION

The blower motor with fan 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.

If the airflow volume is low or the blower speed cannot be changed, the following factors may be the cause.

Symptom Factor
Airflow volume cannot be changed

  • Air conditioning amplifier assembly malfunction

  • Blower motor with fan sub-assembly malfunction

  • Harness or connector

WIRING DIAGRAM

B006YWUE14
*a from Battery
*b Air Conditioning Amplifier Assembly
*c Blower Motor with Fan Sub-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


    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. 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 motor with fan sub-assembly

      Min.: 0

      Max.: 31

      		 -

      Body Electrical > Air Conditioner > Active Test
      Tester Display
      Blower Motor
      Result
      Result Proceed to
      Blower motor with fan sub-assembly does not operate A
      Blower motor with fan sub-assembly operates but does not change speed B

    B

    GO TO STEP 5 Click here

    A

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


    1. Disconnect the A19 blower motor with fan sub-assembly connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A19-3 (+B) - Body ground Always 11 to 14 V
      Standard Resistance
      Tester Connection Condition Specified Condition
      A19-1 (GND) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. Disconnect the K54 air conditioning amplifier assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A19-2 (SI) - K54-6 (BLW) Always Below 1 Ω
      A19-2 (SI) or K54-6 (BLW) - Other terminals and body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. INSPECT BLOWER MOTOR WITH FAN SUB-ASSEMBLY

    B006ZF9C11
    *a

    Front view of wire harness connector

    (to Air Conditioning Amplifier Assembly)

    1. Connect the A19 blower motor with fan sub-assembly connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      K54-6 (BLW) - Body ground Always 4.75 to 5.25 V
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE BLOWER MOTOR WITH FAN SUB-ASSEMBLY Click here

    OK

  5. INSPECT AIR CONDITIONING AMPLIFIER ASSEMBLY

    B006XOFC10
    *a

    Component with harness connected

    (Air Conditioning Amplifier Assembly)

    1. Connect the K54 air conditioning amplifier assembly connector.

    2. Turn the ignition switch to ON.

    3. Set the blower speed to LO.

    4. Using an oscilloscope, check the waveform.

      Item Content
      Terminal No. K54-6 (BLW) - K54-4 (GND)
      Tool Setting 2 V/DIV., 1 ms./DIV.
      Condition

      • Ignition switch ON

      • Blower speed: LO
      OK
      Waveform is similar to that shown in the illustration.

      Tech Tips

      The waveform varies with the blower speed.

      Result
      Proceed to
      OK
      NG

    OK

    REPLACE BLOWER MOTOR WITH FAN SUB-ASSEMBLY Click here

    NG

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here