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 speed signals are transmitted in accordance with changes in the duty ratio.

CAUTION / NOTICE / HINT

PROCEDURE

1. Click here

   PERFORM ACTIVE TEST USING GTS

   
   

   1. Connect the GTS to the DLC3.

   2. Turn the power 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.

      Table 2. Air Conditioner

      Tester Display	Test Part	Control Range	Diagnostic Note
      Blower Motor	blower motor with fan sub-assembly	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

   
   
   • A

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

   • BClick here
   • CClick here
2. Click here

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

   
   

   1. Disconnect the H53 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 H53-1 (GND) - Body ground Always Below 1 Ω

   
   
   • OKClick here
   • NG

     REPAIR OR REPLACE HARNESS OR CONNECTOR

3. Click here

   CHECK HARNESS AND CONNECTOR (BLOWER MOTOR WITH FAN SUB-ASSEMBLY - POWER SOURCE)

   
   

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

      Standard Voltage
      Tester Connection Condition Specified Condition H53-3 (+B) - Body ground Power switch off 11 to 14 V

   
   
   • OKClick here
   • NG

     REPAIR OR REPLACE HARNESS OR CONNECTOR

4. Click here

   CHECK HARNESS AND CONNECTOR (AIR CONDITIONING AMPLIFIER ASSEMBLY - BLOWER MOTOR WITH FAN SUB-ASSEMBLY)

   
   

   1. Disconnect the H54 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 H54-22 (BLW) - H53-2 (SI) Always Below 1 Ω H54-22 (BLW) - Body ground Always 10 kΩ or higher

   
   
   • OKClick here
   • NG

     REPAIR OR REPLACE HARNESS OR CONNECTOR

5. Click here

   INSPECT BLOWER MOTOR WITH FAN SUB-ASSEMBLY

   
   

   1. Reconnect the H53 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 H54-22 (BLW) - Body ground Power switch off 4.5 to 5.5 V

      Table 3. Text in Illustration

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

   
   
   • OKClick here
   • NG

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

6. Click here

   INSPECT AIR CONDITIONING AMPLIFIER ASSEMBLY

   
   
   1. 

      Table 4.

      *a	1 V/DIV.
      *b	500 μs./DIV.

      

      Remove the air conditioning amplifier assembly (Click here).

   2. Reconnect the H54 air conditioning amplifier assembly connector.

   3. Turn the power switch on (IG).

   4. Turn the blower switch on (LO).

   5. Measure the waveform between terminal H54-22 (BLW) of the air conditioning amplifier assembly and body ground.

      OK
      Waveform is similar to that shown in the illustration.

      Tip:

      The waveform varies with the blower speed.

      Item	Content
      Tool setting	1 V/DIV., 500 μs./DIV.
      Vehicle condition	Power switch on (IG) Blower switch LO

      Table 5. Text in Illustration

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

   
   
   • OK

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

   • NG

     REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY (Click here)