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

DESCRIPTION

The blower motor is operated by signals from the air conditioning amplifier. Blower motor speed signals are transmitted in accordance with changes in the duty ratio.

A017ER0E06

WIRING DIAGRAM

A017B1RE07

INSPECTION PROCEDURE

PROCEDURE


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


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch on (IG) and turn the intelligent tester main switch on.

    3. Select the item below in the Active Test, and then check that the blower motor operates.

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

    B

    CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER - BODY GROUND) Click here

    C

    PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE Click here

    A

  2. INSPECT FUSE (HTR)


    1. Remove the HTR fuse from the main body ECU.

    2. Measure the resistance of the HTR fuse.

      Standard resistance
      Tester Connection Condition Specified Condition
      HTR fuse Always Below 1 Ω

    NG

    REPLACE FUSE

    OK

  3. CHECK HARNESS AND CONNECTOR (BLOWER MOTOR - BODY GROUND)


    1. A017FU0E19

      Disconnect the D30 motor connector.

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

      Standard resistance
      Tester Connection Condition Specified Condition
      D30-1 (GND) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. A017FU0E20

      Disconnect the D30 motor connector.

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

      Standard voltage
      Tester Connection Condition Specified Condition
      D30-3 (+B) - Body ground Always 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER - BODY GROUND)


    1. A017BP9E93

      Disconnect the D33 amplifier connector.

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

      Standard voltage
      Tester Connection Condition Specified Condition
      D33-23 (BLW) - D33-14 (GND)

      Ignition switch on (IG)

      Blower switch OFF

      		 4.5 to 5.5 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. CHECK AIR CONDITIONING AMPLIFIER


    1. A017FMSE04

      Remove the air conditioning amplifier with its connectors still connected.

    2. Check the waveform of the amplifier connector.

      OK
      Waveform is as shown in the illustration.

      Tech Tips

      The waveform varies with the blower level.

      Item Content
      Tester Connection BLW (D33-23) - GND (D33-14)
      Tool Setting 1 V/DIV., 500 μsec./DIV.
      Condition

      Ignition switch on (IG)

      Blower switch LO

    NG

    REPLACE AIR CONDITIONING AMPLIFIER Click here

    OK

    REPLACE BLOWER W/ FAN MOTOR SUB-ASSEMBLY Click here