AIR CONDITIONING SYSTEM(for Automatic Air Conditioning System), Diagnostic DTC:B1446/46

DESCRIPTION

• for LHD

  The No. 2 air conditioning radiator damper servo sub-assembly (air mix for driver side) sends pulse signals to inform the air conditioning amplifier assembly of the damper position. The air conditioning amplifier assembly activates the motor (normal or reverse) based on these signals to move the No. 2 air conditioning radiator damper servo sub-assembly (air mix for driver side) to the appropriate position. As a result, the amount of air passing through the heater core after passing through the evaporator is adjusted, and the temperature of the air blowing toward the driver side is controlled.

  The air conditioning amplifier assembly communicates with the servo through a communication/driver IC and wiring assembly called the air conditioning harness assembly.

• for RHD

  The No. 1 air conditioning radiator damper servo sub-assembly (air mix for driver side) sends pulse signals to inform the air conditioning amplifier assembly of the damper position. The air conditioning amplifier assembly activates the motor (normal or reverse) based on these signals to move the No. 1 air conditioning radiator damper servo sub-assembly (air mix for driver side) to the appropriate position. As a result, the amount of air passing through the heater core after passing through the evaporator is adjusted, and the temperature of the air blowing toward the driver side is controlled.

  The air conditioning amplifier assembly communicates with the servo through a communication/driver IC and wiring assembly called the air conditioning harness assembly.

• *1: The air conditioning amplifier assembly stores this DTC if the malfunction has occurred for the period of time indicated in the brackets.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

PROCEDURE

1. CONFIRM MODEL

   
   

   1. Choose the model to be inspected.

      Result
      Result Proceed to for LHD A for RHD B

   
   

   B

   READ VALUE USING GTS Click here

   A

2. READ VALUE USING GTS

   
   

   1. Connect the GTS to the DLC3.

   2. Turn the ignition switch to ON.

   3. Turn the GTS on.

   4. Operate the driver side temperature adjustment switch.

   5. Enter the following menus: Body Electrical / Air Conditioner / Data List.

   6. Check the value(s) by referring to the table below.

      
      Body Electrical > Air Conditioner > Data List

      Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
      Air Mix Servo Targ Pulse(D)	No. 2 air conditioning radiator damper servo sub-assembly (air mix for driver side) target pulse	Min.: 128 Max.: 383	MAX COLD: 5 (pulse) MAX HOT: 103 (pulse)	-
      Air Mix Servo Actual Pulse(D)	No. 2 air conditioning radiator damper servo sub-assembly (air mix for driver side) actual pulse	Min.: 128 Max.: 383	MAX COLD: 5 (pulse) MAX HOT: 103 (pulse)	-

      
      Body Electrical > Air Conditioner > Data List

      Tester Display
      Air Mix Servo Targ Pulse(D)
      Air Mix Servo Actual Pulse(D)

      OK
      When the driver side temperature adjustment switch is turned from MAX COLD to MAX HOT, the actual pulse changes following the target pulse.

      Result
      Result Proceed to Target pulse changes but actual pulse does not change A Target pulse and actual pulse do not change B Actual pulse changes following the target pulse (When troubleshooting according to the DTC) C Actual pulse changes following the target pulse (When troubleshooting according to Problem Symptoms Table) D

   
   

   B

   REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

   C

   RECONFIRM DTC OUTPUT Click here

   D

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

   A

3. REPLACE NO. 2 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY (AIR MIX for Driver Side)

   
   

   1. Replace the No. 2 air conditioning radiator damper servo sub-assembly (air mix for driver side).

      Click here

      Tech Tips

      Since the servo motor cannot be inspected while it is removed from the vehicle, replace the servo motor with a new or known good one and check that the condition returns to normal.

   2. Check for DTCs.

      Click here

      
      Body Electrical > Air Conditioner > Trouble Codes

      Result
      Result Proceed to DTC B1446/46 is output A DTC B1446/46 is not output B

   
   

   B

   END (NO. 2 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY (AIR MIX for Driver Side) WAS DEFECTIVE)

   A

4. REPLACE AIR CONDITIONING HARNESS ASSEMBLY

   
   

   1. Replace the air conditioning harness assembly.

      Click here

      Tech Tips

      Since the air conditioning harness assembly cannot be inspected while it is removed from the vehicle, replace the air conditioning harness assembly with a new or known good one and check that the condition returns to normal.

   2. Check for DTCs.

      Click here

      
      Body Electrical > Air Conditioner > Trouble Codes

      Result
      Result Proceed to DTC B1446/46 is output A DTC B1446/46 is not output B

   
   

   A

   REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

   B

   END (AIR CONDITIONING HARNESS ASSEMBLY WAS DEFECTIVE)

5. RECONFIRM DTC OUTPUT

   
   

   1. Check for DTCs.

      Click here

      
      Body Electrical > Air Conditioner > Trouble Codes

      Result
      Result Proceed to DTC B1446/46 is output A DTC B1446/46 is not output B

   
   

   A

   REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

   B

   USE SIMULATION METHOD TO CHECK Click here

6. READ VALUE USING GTS

   
   

   1. Connect the GTS to the DLC3.

   2. Turn the ignition switch to ON.

   3. Turn the GTS on.

   4. Operate the driver side temperature adjustment switch.

   5. Enter the following menus: Body Electrical / Air Conditioner / Data List.

   6. Check the value(s) by referring to the table below.

      
      Body Electrical > Air Conditioner > Data List

      Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
      Air Mix Servo Targ Pulse(D)	No. 1 air conditioning radiator damper servo sub-assembly (air mix for driver side) target pulse	Min.: 128 Max.: 383	MAX COLD: 105 (pulse) MAX HOT: 7 (pulse)	-
      Air Mix Servo Actual Pulse(D)	No. 1 air conditioning radiator damper servo sub-assembly (air mix for driver side) actual pulse	Min.: 128 Max.: 383	MAX COLD: 105 (pulse) MAX HOT: 7 (pulse)	-

      
      Body Electrical > Air Conditioner > Data List

      Tester Display
      Air Mix Servo Targ Pulse(D)
      Air Mix Servo Actual Pulse(D)

      OK
      When the driver side temperature adjustment switch is turned from MAX COLD to MAX HOT, the actual pulse changes following the target pulse.

      Result
      Result Proceed to Target pulse changes but actual pulse does not change A Target pulse and actual pulse do not change B Actual pulse changes following the target pulse (When troubleshooting according to the DTC) C Actual pulse changes following the target pulse (When troubleshooting according to Problem Symptoms Table) D

   
   

   B

   REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

   C

   RECONFIRM DTC OUTPUT Click here

   D

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

   A

7. REPLACE NO. 1 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY (AIR MIX for Driver Side)

   
   

   1. Replace No. 1 air conditioning radiator damper servo sub-assembly (air mix for driver side).

      Click here

      Tech Tips

      Since the servo motor cannot be inspected while it is removed from the vehicle, replace the servo motor with a new or known good one and check that the condition returns to normal.

   2. Check for DTCs.

      Click here

      
      Body Electrical > Air Conditioner > Trouble Codes

      Result
      Result Proceed to DTC B1446/46 is output A DTC B1446/46 is not output B

   
   

   B

   END (NO. 1 AIR CONDITIONING RADIATOR DAMPER SERVO SUB-ASSEMBLY (AIR MIX for Driver Side) WAS DEFECTIVE)

   A

8. REPLACE AIR CONDITIONING HARNESS ASSEMBLY

   
   

   1. Replace the air conditioning harness assembly.

      Click here

      Tech Tips

      Since the air conditioning harness assembly cannot be inspected while it is removed from the vehicle, replace the air conditioning harness assembly with a new or known good one and check that the condition returns to normal.

   2. Check for DTCs.

      Click here

      
      Body Electrical > Air Conditioner > Trouble Codes

      Result
      Result Proceed to DTC B1446/46 is output A DTC B1446/46 is not output B

   
   

   A

   REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

   B

   END (AIR CONDITIONING HARNESS ASSEMBLY WAS DEFECTIVE)

9. RECONFIRM DTC OUTPUT

   
   

   1. Check for DTCs.

      Click here

      
      Body Electrical > Air Conditioner > Trouble Codes

      Result
      Result Proceed to DTC B1446/46 is output A DTC B1446/46 is not output B

   
   

   A

   REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

   B

   USE SIMULATION METHOD TO CHECK Click here