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

DESCRIPTION

A01E25YE09

The blower with fan motor sub-assembly is operated by signals from the air conditioning amplifier. Blower with fan motor sub-assembly speed signals are determined by changes in the duty ratio*.

The blower motor control controls the blower with fan motor sub-assembly speed. The blower motor control reads the signal from the air conditioning amplifier assembly and controls rotation and speed.

Tech Tips

*: The duty ratio is the ratio of the blower with fan motor sub-assembly on time (A) to the total of the blower with fan motor sub-assembly on and off time (A + B).

WIRING DIAGRAM

A01E0AEE03

INSPECTION PROCEDURE

Note

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

PROCEDURE


  1. PERFORM ACTUATOR CHECK


    1. Enter actuator check mode Click here.

    2. Place your hand in front of a vent and check that the air flow level changes according to the display code.

      Display Code Blower Level
      0 0
      1 1
      2 16
      3 16
      4 16
      5 16
      6 16
      7 16
      8 16
      9 31
      OK
      Blower level changes in accordance with each display code.

      Tech Tips

      The progression through the steps of the actuator check can be changed from automatic to manual by pressing the front DEF switch.


    NG

    CHECK HARNESS AND CONNECTOR (BLOWER MOTOR CONTROL - AIR CONDITIONING AMPLIFIER 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 - AIR CONDITIONING AMPLIFIER AND BODY GROUND)


    1. Disconnect the B10 blower motor control connector.

    2. Disconnect the A44 air conditioning amplifier assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      B10-3 (SI) - A44-2 (BLW) Always Below 1 Ω
      B10-4 (GND) - Body ground
      B10-3 (SI) - Body ground Always 10 kΩ or higher
      B10-2 (+B) - Body ground
      B10-1 (VM) - Body ground

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. INSPECT BLOWER WITH FAN MOTOR SUB-ASSEMBLY


    1. A01E0GZ

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

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

      OK
      Measurement Condition Specified Condition

      Battery positive (+) → Terminal 2

      Battery negative (-) → Terminal 1

      		 The blower motor operates smoothly

    NG

    REPLACE BLOWER WITH FAN MOTOR SUB-ASSEMBLY Click here

    OK

  4. CHECK HARNESS AND CONNECTOR (BLOWER MOTOR CONTROL AND BLOWER WITH FAN MOTOR - BATTERY)


    1. Disconnect the B10 blower motor control connector.

    2. Disconnect the B7 blower with fan motor sub-assembly connector.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      B10-2 (+B) - Body ground

      • Ignition switch ON

      • Blower switch on (LO level)

      		 11 to 14 V

      • Ignition switch ON

      • Blower switch off

      		 Below 1 V
      B7-2 - Body ground

      • Ignition switch ON

      • Blower switch on (LO level)

      		 11 to 14 V

      • Ignition switch ON

      • Blower switch off

      		 Below 1 V
      Standard Resistance
      Tester Connection Condition Specified Condition
      B7-1 - Body ground Always 10 kΩ or higher
      B7-2 - Body ground

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. Disconnect the B10 blower motor control connector.

    2. Disconnect the B7 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
      B10-1 (VM) - B7-1 Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY


    1. A01DW8YE15
      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 of the amplifier.

      Measurement Condition
      Item Content
      Tester Connection A44-2 (BLW) - Body ground
      Tool Setting 1 V/DIV., 50 μsec./DIV.
      Condition Ignition switch ON, Blower switch on (LO level)
      OK
      Waveform is as shown in the illustration.

      Tech Tips

      Waveform varies depending on the blower switch setting.


    NG

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    OK

    REPLACE BLOWER MOTOR CONTROL Click here