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 through the blower resistor. Blower motor speed signals are transmitted in accordance with changes in the duty ratio. The blower motor speed becomes slower when the duty interval is wider, and the blower motor speed becomes faster when the duty interval is narrower.

WIRING DIAGRAM

A001X1ZE02

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 ignition switch 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.: 100

      		 Operates between 0 to 100 %

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

    A

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

    C

    GO TO STEP 7 Click here

    B

  2. INSPECT BLOWER MOTOR WITH FAN SUB-ASSEMBLY


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

      Click here

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

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE BLOWER MOTOR WITH FAN SUB-ASSEMBLY Click here

    OK

  3. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING HARNESS ASSEMBLY (BLOWER ASSEMBLY) - POWER SOURCE)


    1. Disconnect the F8 air conditioning harness assembly (blower assembly) connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      F8-1 - F8-2 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
      F8-2 - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. INSPECT AIR CONDITIONING HARNESS ASSEMBLY (BLOWER ASSEMBLY)


    1. Remove the air conditioning harness assembly (blower assembly).

      Click here

    2. A001SU7C07
      *a

      Front view of wire harness connector

      (to Air Conditioning Harness Assembly (Blower Assembly))
      *b

      Front view of wire harness connector

      (to blower motor with fan sub-assembly)
      *c

      Front view of wire harness connector

      (to blower resistor)
      *d

      Front view of wire harness connector

      (to Air Conditioning Harness Assembly (Heater Radiator Unit Sub-assembly))

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      F8-1 - F7b-3 (+B) Always Below 1 Ω
      A-1 - F7b-2 (+) Always Below 1 Ω
      A-2 - F7b-1 (-) Always Below 1 Ω
      F8-2 - F7b-6 (GND) Always Below 1 Ω
      w-7 - F7b-5 (SI) Always Below 1 Ω
      F8-1 or F7b-3 (+B) - Body ground Always 10 kΩ or higher
      A-1 or F7b-2 (+) - Body ground Always 10 kΩ or higher
      A-2 or F7b-1 (-) - Body ground Always 10 kΩ or higher
      F8-2 or F7b-6 (GND) - Body ground Always 10 kΩ or higher
      w-7 or F7b-5 (SI) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE AIR CONDITIONING HARNESS ASSEMBLY (BLOWER ASSEMBLY) Click here

    OK

  5. INSPECT AIR CONDITIONING HARNESS ASSEMBLY (HEATER RADIATOR UNIT SUB-ASSEMBLY)


    1. Remove the air conditioning harness assembly (heater radiator unit sub-assembly).

      Click here

    2. A001Y4JC02
      *a

      Front view of wire harness connector

      (to Air Conditioning Amplifier Assembly)
      *b

      Front view of wire harness connector

      (to Air Conditioning Harness Assembly (blower assembly))

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      w-7 - F7A-40 Always Below 1 Ω
      w-7 or F7A-40 - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE AIR CONDITIONING HARNESS ASSEMBLY (BLOWER ASSEMBLY) Click here

    OK

  6. INSPECT BLOWER RESISTOR


    1. Reconnect the F7b blower resistor connector.

    2. Reconnect the w air conditioning harness assembly (blower assembly) connector.

    3. A001VXXC02
      *a

      Front view of wire harness connector

      (to Air Conditioning Amplifier Assembly)

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      F7bA-40 (BLW) - Body ground

      • Ignition switch ON

      • Blower switch: Lo

      		 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE BLOWER RESISTOR Click here

    OK

  7. INSPECT AIR CONDITIONING AMPLIFIER ASSEMBLY


    1. Reconnect the F7A air conditioning amplifier assembly connector.

    2. Turn the ignition switch ON.

    3. Turn the blower switch Lo.

    4. Connect an oscilloscope to terminals F7A-40 (BLW) and F72-29 (GND) of the air conditioning amplifier assembly and check the waveform.

      OK
      Waveform is similar to that shown in the illustration.

      Tech Tips

      The waveform varies with the blower speed.

      Item Content
      Tool Setting 2 V/DIV., 1 ms./DIV.
      Vehicle Condition

      • Ignition switch ON

      • Blower switch: Lo
      A001V9FC04
      *a Component with harness connected (Air Conditioning Amplifier Assembly) - -
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE BLOWER RESISTOR Click here

    NG

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here