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

DESCRIPTION

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

WIRING DIAGRAM

A0099PME03

INSPECTION PROCEDURE

Note

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

PROCEDURE


  1. PERFORM ACTIVE TEST USING INTELLIGENT TESTER (REAR BLOWER WITH FAN MOTOR)


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

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

    NG

    CHECK HARNESS AND CONNECTOR (BLOWER MOTOR CONTROL - BATTERY AND BODY GROUND) Click here

    OK

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

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


    1. A0097PKE04
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Blower Motor Control)

      Disconnect the Q12 control connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      Q12-1 (+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
      Q12-6 (GND) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. INSPECT REAR BLOWER WITH FAN MOTOR SUB-ASSEMBLY


    1. A0097H1

      Remove the rear blower with fan motor sub-assembly Click here.

    2. Apply battery voltage to the rear blower with fan motor sub-assembly and check the operation of the rear blower with fan motor sub-assembly.

      OK
      Measurement Condition Specified Condition

      Battery positive (+) → Terminal 2

      Battery negative (-) → Terminal 1

      		 Rear blower with fan motor sub-assembly operation is normal

    NG

    REPLACE REAR BLOWER WITH FAN MOTOR SUB-ASSEMBLY Click here

    OK

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


    1. Disconnect the G24 amplifier connector.

    2. Disconnect the Q12 control connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      G24-22 (BLWH) - Q12-3 (SI) Always Below 1 Ω
      G24-22 (BLWH) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. CHECK HARNESS AND CONNECTOR (BLOWER MOTOR CONTROL - REAR BLOWER WITH FAN MOTOR)


    1. Disconnect the Q12 control connector.

    2. Disconnect the Q14 motor connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      Q12-2 (VM) - Q14-2 Always Below 1 Ω
      Q12-2 (VM) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. CHECK HARNESS AND CONNECTOR (REAR BLOWER WITH FAN MOTOR - BODY GROUND)


    1. A0093XOE03
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Rear Blower with Fan Motor Sub-assembly)

      Disconnect the Q14 motor connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      Q14-1 - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  7. CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY


    1. A0094NNE03
      Text in Illustration
      *a

      Component with harness connected

      (Air Conditioning Amplifier Assembly)

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

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      G24-22 (BLWH) - G24-20 (RGND) Always 4.5 to 7 V

    NG

    REPLACE BLOWER MOTOR CONTROL Click here

    OK

  8. CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY


    1. A00967QE03
      Text in Illustration
      *a

      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.

      Item Content
      Terminal No. (Symbol) G24-22 (BLWH) - G20-20 (RGND)
      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

  9. REPLACE BLOWER MOTOR CONTROL


    1. Replace the blower motor control with a new or normally functioning one Click here.

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

      OK
      Rear blower with fan motor sub-assembly operates normally.

    NG

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    OK

    END (BLOWER MOTOR CONTROL IS FAULTY)