AIR CONDITIONING SYSTEM > Blower Motor Circuit

for Preparation Click here


DESCRIPTION

E110709E01
The blower motor is operated by signals from the A/C amplifier assembly. Blower motor speed signals are transmitted by changes in the duty ratio.
Duty Ratio:
  1. The duty ratio is the ratio of the period of continuity in one cycle. For example, A is the period of continuity in one cycle, and B is the period of non-continuity.

WIRING DIAGRAM


E109235E04


INSPECTION PROCEDURE

1.READ VALUE OF INTELLIGENT TESTER

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch ON and push the intelligent tester main switch on.

  1. Select the item below in the DATA LIST, and read the display on the intelligent tester.


DATA LIST / AIR CONDITIONER 
Item
Measurement Item/Display
(Range)
Normal Condition
Diagnostic Note
BLOWER LEVEL
Blower motor speed level /min.: Level 0 max.: Level 31
Changes depending on blower level
-

OK:
The display is as specified in the normal condition.



NG
Go to step 2
OK

PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE 

2.PERFORM ACTIVE TEST BY INTELLIGENT TESTER

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch ON and push the intelligent tester main switch on.

  1. Select the item below in the ACTIVE TEST and then check that the blower motor operates.


ACTIVE TEST / AIR CONDITIONER 
Item
Test Details/Display
(Range)
Diagnostic Note
BLOWER MOTOR
Blower motor /min.: Level 0 max.: Level 31
-

OK:
Blower motor operates and blower level changes.



NG
Go to step 3
OK

PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE 

3.PERFORM ACTUATOR CHECK

  1. Set the actuator check mode (Click here).

  1. Press the blower switch to set the step operation.

  1. Check for air flow level by hand.


Display Code
Blower Level
0
0
1
1
2
17
3
17
4
17
5
17
6
17
7
17
8
17
9
31

OK:
Blower level changes in accordance with each display code.



NG
Go to step 4
OK

PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE 

4.CHECK HARNESS AND CONNECTOR (BLOWER MOTOR CONTROLLER - A/C AMPLIFIER ASSEMBLY)


    E109229E03

  1. Disconnect the connector from the A/C amplifier assembly and the blower motor controller.

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

    Resistance:
    Tester connection
    (Symbols)
    		Condition
    		Specified condition
    A11-9 (BLW) - B3-2
    		Always
    		Below 1 Ω
    A11-9 (BLW) - Body ground
    		Always
    		10 kΩ or higher



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


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


    E108934E02

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

    Resistance:
    Tester connection
    		Condition
    		Specified condition
    B3-1 - Body ground
    		Always
    		Below 1 Ω



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


6.CHECK HARNESS AND CONNECTOR (BLOWER MOTOR CONTROLLER - BLOWER MOTOR)


    E109303E01

  1. Disconnect the connector from the blower motor.

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

    Voltage:
    Tester connection
    		Condition
    		Specified condition
    B2-2 - Body ground
    		Ignition switch ON
    Blower switch: ON
    		10 to 14 V
    B3-3 - Body ground
    		Ignition switch ON
    Blower switch: ON
    		10 to 14 V
    B2-2 - Body ground
    		Ignition switch ON
    Blower switch: OFF
    		Below 1 V
    B3-3 - Body ground
    		Ignition switch ON
    Blower switch: OFF
    		Below 1 V



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


7.CHECK HARNESS AND CONNECTOR (BLOWER MOTOR CONTROLLER - BLOWER MOTOR)


    E109303E01

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

    Resistance:
    Tester connection
    		Condition
    		Specified condition
    B2-1 - B3-4
    		Always
    		Below 1 Ω
    B2-1 - Body ground
    		Always
    		10 kΩ or higher



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


8.INSPECT COOLING UNIT MOTOR SUB-ASSEMBLY W/FAN


    E109230E01

  1. Remove the cooling unit motor sub-assembly w/ fan.

  1. Connect the negative (-) lead connected to terminal 1 of the blower motor connector, the positive (+) lead to terminal 2.

OK:
Blower motor operates smoothly.



NG
REPLACE COOLING UNIT MOTOR SUB-ASSEMBLY W/FAN
OK


9.INSPECT AIR CONDITIONING AMPLIFIER ASSEMBLY

  1. Reconnect the connector to the A/C amplifier assembly.



    E109265E23

  1. Remove the A/C amplifier assembly with the connectors still connected.

  1. Turn the ignition switch to the ON position.

  1. Blower speed switch is at "LO".



    E108906E07

  1. Measure the waveform between terminal BLW (A11-9) of the A/C amplifier assembly and body ground.

    OK:
    Waveform operate as shown in the illustration.

    HINT:
    Waveform cycle varies with the blower level.



NG
REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY
OK

REPLACE BLOWER MOTOR CONTROLLER