AIR CONDITIONING SYSTEM > Blower Motor Circuit

for Preparation Click here


DESCRIPTION

The blower with fan motor sub-assembly (blower motor) 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


E192387E03


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

  1. Connect the intelligent tester to the DLC3.

  1. Turn the power switch on (IG).

  1. Turn the intelligent tester on.

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

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


Air Conditioner 
Tester Display
Test Part
Control Range
Diagnostic Note
Blower Motor
Blower with fan motor sub-assembly (blower motor)
Min.: 0, Max.: 31
-

OK:
Blower with fan motor sub-assembly (blower motor) operates and blower motor speed level changes.


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 6
A

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

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

  1. Disconnect the H13 blower with fan motor sub-assembly (blower motor) connector.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    H13-3 (GND) - Body ground
    		Always
    		Below 1 Ω



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


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

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

    Standard Voltage:
    Tester Connection
    		Condition
    		Specified Condition
    H13-1 (+B) - Body ground
    		Power switch off
    		11 to 14 V



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


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

  1. Disconnect the H85 air conditioning amplifier assembly connector.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    H85-23 (BLW) - H13-2 (SI)
    		Always
    		Below 1 Ω
    H85-23 (BLW) - Body ground
    		Always
    		10 kΩ or higher



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


5.INSPECT BLOWER WITH FAN MOTOR SUB-ASSEMBLY (BLOWER MOTOR)

  1. Reconnect the H13 blower with fan motor sub-assembly (blower motor) connector.



    E222797E02

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

    Standard Voltage:
    Tester Connection
    		Condition
    		Specified Condition
    H85-23 (BLW) - Body ground
    		Power switch off
    		4.5 to 5.5 V

    Text in Illustration 
    *a
    		Front view of wire harness connector
    (to Air Conditioning Amplifier Assembly)



NG
REPLACE BLOWER WITH FAN MOTOR SUB-ASSEMBLY (Click here)
OK


6.INSPECT AIR CONDITIONING AMPLIFIER ASSEMBLY


    E127604E33

  1. Remove the air conditioning amplifier assembly.

  1. Reconnect the H85 air conditioning amplifier assembly connector.

  1. Turn the power switch on (IG).

  1. Set the blower speed to low.

  1. Measure the waveform between terminal H85-23 (BLW) of the air conditioning amplifier assembly and body ground.
    Item
    		Content
    Tool setting
    		1 V/DIV., 500 μs/DIV.
    Vehicle condition
    		Power switch on (IG)
    Blower set to low

    OK:
    Waveform is as shown in the illustration.

    HINT:
    The waveform varies with the blower speed.

    Text in Illustration 
    *a
    		Component with harness connected
    (Air Conditioning Amplifier Assembly)



NG
REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY (Click here)
OK

REPLACE BLOWER WITH FAN MOTOR SUB-ASSEMBLY (Click here)