DTC    B1446/46    Air Mix Damper Control Servo Motor Circuit (Driver Side)

for Preparation Click here


DESCRIPTION

The air mix control servo motor (for driver side) sends pulse signals to indicate the damper position to the air conditioning amplifier assembly. The air conditioning amplifier assembly activates the motor (normal or reverse) based on these signals to move the air mix control servo motor (for driver side) to any 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.

HINT:
Confirm that no mechanical problem is present because this DTC can be stored when either a damper link or the damper is mechanically locked.


DTC No.
DTC Detection Condition
Trouble Area
B1446/46
Air mix damper position sensor value does not change even if air conditioning amplifier assembly operates air mix control servo motor
  1. Air mix control servo motor (for driver side)
  2. Air conditioning harness assembly
  3. Air conditioning amplifier assembly

WIRING DIAGRAM


E219972E04


INSPECTION PROCEDURE

1.READ VALUE 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. Operate the driver side temperature adjustment switch.

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

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

    Air Conditioner 
    Tester Display
    		Measurement Item/Range
    		Normal Condition
    		Diagnostic Note
    Air Mix Servo Targ Pulse (D)
    		Driver side air mix servo motor target pulse / Min.: 0, Max.: 255
    		for LHD:
    MAX. COLD: 92 (pulse)
    MAX. HOT: 5 (pulse)
    for RHD:
    MAX. COLD: 6 (pulse)
    MAX. HOT: 93 (pulse)
    		-
    Air Mix Servo Actual Pulse (D)
    		Driver side air mix servo motor actual pulse / Min.: 0, Max.: 255
    		for LHD:
    MAX. COLD: 92 (pulse)
    MAX. HOT: 5 (pulse)
    for RHD:
    MAX. COLD: 6 (pulse)
    MAX. HOT: 93 (pulse)
    		-

    OK:
    The display is as specified in the Normal Condition column.


    Result:

    Result
    		Proceed to
    NG
    		A
    OK (When troubleshooting according to Problem Symptoms Table)
    		B
    OK (When troubleshooting according to the DTC)
    		C



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

C
REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY (Click here)
A


2.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
    Air Mix Servo Targ Pulse (D)
    		Air mix servo motor pulse (for driver side)
    		Min.: 0, Max.: 255
    		-

    OK:
    Air temperature changes in accordance with each control range.



NG
Go to step 3
OK

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY (Click here)  

3.INSPECT AIR MIX CONTROL SERVO MOTOR (FOR DRIVER SIDE)

  1. Replace the air mix control servo motor (for driver side) (Click here).

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

  1. Check for the DTC.

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



B
END (AIR MIX CONTROL SERVO MOTOR WAS DEFECTIVE)
A


4.INSPECT AIR CONDITIONING HARNESS ASSEMBLY

  1. Replace the air conditioning harness assembly (Click here).

    HINT:
    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 a known good one and check that the condition returns to normal.

  1. Check for the DTC.

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



B
END (AIR CONDITIONING HARNESS ASSEMBLY WAS DEFECTIVE)
A

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY (Click here)