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

for Preparation Click here


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.

E115031E09


WIRING DIAGRAM


E177532E01


INSPECTION PROCEDURE

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

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

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch to ON.

  1. Turn the intelligent tester on.

  1. Enter the following menus: Body / Air Conditioner / Active Test / Blower Motor.

  1. According to the display on the intelligent tester, check blower motor operation while performing the Active Test.

    Air Conditioner 
    Tester Display
    		Test Part
    		Condition Range
    		Diagnostic Note
    Blower Motor
    		Blower motor
    		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
Go to step 2

C
Go to step 5
A

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

2.CHECK HARNESS AND CONNECTOR (BLOWER MOTOR - BODY GROUND)
E115959E23

  1. Disconnect the D12 blower motor connector.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    D12-1 (GND) - Body ground
    		Always
    		Below 1 Ω

  1. Reconnect the blower motor connector.
    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to Blower Motor)



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


3.CHECK HARNESS AND CONNECTOR (BLOWER MOTOR - BATTERY)
E115959E24

  1. Disconnect the D12 blower motor connector.

  1. Turn the ignition switch to ON.

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

Standard Voltage:
Tester Connection
Switch Condition
Specified Condition
D12-3 (+B) - D12-1 (GND)
Ignition switch ON
11 to 14 V

  1. Reconnect the blower motor connector.
    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to Blower Motor)



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


4.INSPECT BLOWER MOTOR
E107336E20

  1. Disconnect the D15 air conditioning amplifier connector.

  1. Connect the D12 blower motor connector.

  1. Turn the ignition switch to ON.

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

    Standard Voltage:
    Tester Connection
    		Switch Condition
    		Specified Condition
    D12-2 (SI) - D12-1 (GND)
    		Ignition switch ON
    		4.5 to 5.5 V

  1. Reconnect the air conditioning amplifier connector.
    Text in Illustration 
    *1
    		Component with harness connected
    (Blower Motor)



NG
REPLACE BLOWER MOTOR (Click here)
OK


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


    E115961E13

  1. Disconnect the D15 air conditioning amplifier connector.

  1. Turn the ignition switch to ON.

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

    Standard Voltage:
    Tester Connection
    		Switch Condition
    		Specified Condition
    D15-23 (BLW) - D15-14 (GND)
    		Ignition switch ON
    		4.5 to 5.5 V

  1. Reconnect the air conditioning amplifier connector.
    Text in Illustration 
    *1
    		Rear view of wire harness connector
    (to Air Conditioning Amplifier)



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


6.INSPECT AIR CONDITIONING AMPLIFIER


    E115962E09

  1. Remove the air conditioning amplifier with its connectors still connected (Click here).

  1. Turn the ignition switch to on.

  1. Check the waveform between terminal D15-23 (BLW) of the air conditioning amplifier and the body ground.

    OK:
    Waveform is as shown in the illustration.

    HINT:
    The waveform varies with the blower level.

    Item
    		Content
    Tester range
    		1 V / DIV., 500 μs / DIV.
    Condition
    		Ignition switch ON
    Blower switch on (Lo)

    HINT:
    Waveform varies with the blower level.

  1. Reinstall the air conditioning amplifier.



NG
REPLACE AIR CONDITIONING AMPLIFIER (Click here)
OK

REPLACE BLOWER MOTOR (Click here)