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.

WIRING DIAGRAM

A01I3JXE08

INSPECTION PROCEDURE

Note

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

PROCEDURE


  1. PERFORM ACTIVE TEST USING TECHSTREAM


    1. Connect the Techstream to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the Techstream on.

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

    5. Check the operation by referring to the table below.

      Air Conditioner
      Tester Display Test Part Control Range Diagnostic Note
      Blower Motor blower motor with fan sub-assembly Min.: 0, Max.: 31 -
      Result
      Result Proceed to
      OK A
      NG (blower motor does not operate) B
      NG (blower motor operates but does not change speed) C

    B

    CHECK HARNESS AND CONNECTOR (BLOWER MOTOR WITH FAN SUB-ASSEMBLY - BODY GROUND) Click here

    C

    INSPECT AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    A

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

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


    1. Disconnect the I76 blower motor with fan sub-assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      I76-1 (GND) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


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

      Standard Voltage
      Tester Connection Condition Specified Condition
      I76-3 (+B) - Body ground Power switch off 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. Disconnect the I77 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
      I77-22 (BLW) - I76-2 (SI) Always Below 1 Ω
      I77-22 (BLW) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. INSPECT BLOWER MOTOR WITH FAN SUB-ASSEMBLY


    1. Reconnect the I76 blower motor with fan sub-assembly connector.

    2. A01I2PVE08
      Text in Illustration
      *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 Condition Specified Condition
      I77-22 (BLW) - Body ground Power switch off 4.5 to 5.5 V

    NG

    REPLACE BLOWER MOTOR WITH FAN SUB-ASSEMBLY Click here

    OK

  6. INSPECT AIR CONDITIONING AMPLIFIER ASSEMBLY


    1. A01I3XKE01
      Text in Illustration
      *a

      Component with harness connected

      (Air Conditioning Amplifier Assembly)

      Remove the air conditioning amplifier assembly Click here.

    2. Reconnect the I77 air conditioning amplifier assembly connector.

    3. Turn the power switch on (IG).

    4. Turn the blower switch on (LO).

    5. Measure the waveform between terminal I77-22 (BLW) of the air conditioning amplifier assembly and body ground.

      OK
      Waveform is similar to that shown in the illustration.

      Tech Tips

      The waveform varies with the blower speed.

      Item Content
      Tool setting 1 V/DIV., 500 μs/DIV.
      Vehicle condition

      Power switch on (IG)

      Blower switch on (LO)

    NG

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    OK

    REPLACE BLOWER MOTOR WITH FAN SUB-ASSEMBLY Click here