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 with fan sub-assembly speed signals are transmitted in accordance with changes in the duty ratio.

WIRING DIAGRAM

B002E5RE04
*a from Battery
*b Air Conditioning Amplifier Assembly
*c Blower Motor with Fan Sub-assembly

CAUTION / NOTICE / HINT

Note


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

  • Before disconnecting the cable from the negative (-) battery terminal or replacing the air conditioning amplifier assembly, record the last operation state of the air conditioning for each transmitter. After replacement, it is necessary to perform memory registration for each transmitter.

    Click here

PROCEDURE


  1. PERFORM ACTIVE TEST USING GTS


    1. Connect the GTS to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the GTS on.

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

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


      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.: 31 -

      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 6 Click here

    B

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


    1. Disconnect the A20 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
      A20-1 (GND) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A20-3 (+B) - Body ground Always 11 to 14 V
      Result
      Proceed to
      OK
      NG

    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 K64 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
      K64-3 (BLW) - A20-2 (SI) Always Below 1 Ω
      K64-3 (BLW) or A20-2 (SI) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. CHECK BLOWER MOTOR WITH FAN SUB-ASSEMBLY


    1. Reconnect the A20 blower motor with fan sub-assembly connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      K64-3 (BLW) - Body ground Always 4.5 to 5.5 V
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE BLOWER MOTOR WITH FAN SUB-ASSEMBLY Click here

    OK

  6. CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY


    1. Remove the air conditioning amplifier assembly.

      Click here

    2. Reconnect the A20 blower motor with fan sub-assembly connector.

    3. Reconnect the K64 air conditioning amplifier assembly connector.

    4. Turn the engine switch on (IG).

    5. Turn the blower switch on (LO).

    6. B002EZAC01
      *a

      Component with harness connected

      (Air Conditioning Amplifier Assembly)

      Measure the waveform between terminal K64-3 (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
      Terminal No. (Symbol) K64-3 (BLW) - Body ground
      Tool setting 1 V/DIV., 500 μs/DIV.
      Vehicle condition

      • Engine switch on (IG)

      • Blower switch: Lo
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE BLOWER FAN MOTOR ASSEMBLY Click here

    NG

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here