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

Vehicle Interior. Land Cruiser. Urj200, 202 Grj200 Vdj200
Heating Air Conditioning. Land Cruiser. Urj200, 202 Grj200 Vdj200

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

READ VALUE USING GTS (AIR MIX SERVO TARG PULSE[D], AIR MIX SERVO ACTUAL PULSE[D])

CHECK AIR MIX DAMPER SERVO MOTOR

CHECK AIR CONDITIONING HARNESS ASSEMBLY

CHECK FOR DTC

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


DESCRIPTION

The air mix damper servo motor 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 the signals to move the air mix damper servo motor to any position. As a result, the amount of air that has passed through the evaporator and is passing through the heater core is adjusted, and the temperature of the air blowing toward the driver side is controlled.
HINT:
Confirm that no mechanical problem is present because this trouble code can be output when either a damper link or damper is mechanically locked.

DTC Code
DTC Detection Condition
Trouble Area
B1446/46
The air mix damper position does not change even if the air conditioning amplifier assembly operates the air mix damper servo motor.
  1. Air mix damper servo motor
  2. Air conditioning harness assembly
  3. Air conditioning amplifier assembly

WIRING DIAGRAM


Land Cruiser. Urj200, 202 Grj200 Vdj200.Heating Air Conditioning.Air Conditioning System (For Automatic Air Conditioning System). Dtc B1446/46 Air Mix Damper Control Servo Motor Circuit (Driver Side)


INSPECTION PROCEDURE

1.READ VALUE USING GTS (AIR MIX SERVO TARG PULSE[D], AIR MIX SERVO ACTUAL PULSE[D])

  1. Use the Data List to check if the air mix damper servo motor is functioning properly (Click here).

    Air Conditioner
    Tester Display
    		Measurement Item/Range
    		Normal Condition
    		Diagnostic Note
    Air Mix Servo Targ Pulse(D)
    		Air mix damper servo motor target pulse / Min.: 128, Max.:383
    for LHD:
    1. MAX COLD: 218 (pulse)
    2. MAX HOT: 136 (pulse)
    for RHD:
    1. MAX COLD: 136 (pulse)
    2. MAX HOT: 218 (pulse)
    1. Displayed between 136 and 218 pulse
    2. Air mix damper servo motor system malfunction
    Air Mix Servo Actual Pulse(D))
    		Air mix damper servo motor actual pulse / Min.: 128, Max.:383
    for LHD:
    1. MAX COLD: 218 (pulse)
    2. MAX HOT: 136 (pulse)
    for RHD:
    1. MAX COLD: 136 (pulse)
    2. MAX HOT: 218 (pulse)
    1. Displayed between 136 and 218 pulse
    2. Air mix damper servo motor system malfunction
    OK:
    When the temperature adjustment switch is turned 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
Go to step 4

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


2.CHECK AIR MIX DAMPER SERVO MOTOR

  1. Replace the air mix damper servo motor.

    1. for LHD: Click here
    2. for RHD: Click here

    1. R LH ().

HINT:
Since the servo motor cannot be inspected while it is removed from the vehicle, replace the servo motor with a normal one.

  1. Clear the DTCs (Click here).

  1. Check for DTCs (Click here).

    OK :
    DTC B1446/46 is not output.


NG
Go to step 3
OK

END (AIR MIX DAMPER SERVO MOTOR WAS DEFECTIVE)

3.CHECK AIR CONDITIONING HARNESS ASSEMBLY

  1. Replace the air conditioning harness assembly with a new or known good one.

    1. for LHD: Click here
    2. for RHD: Click here

  1. Clear the DTCs (Click here).

  1. Check for DTCs (Click here).

    OK :
    DTC B1446/46 is not output.


NG
REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY (Click here)
OK

END (AIR CONDITIONING HARNESS ASSEMBLY WAS DEFECTIVE)

4.CHECK FOR DTC

  1. Clear the DTCs (Click here ).

  1. Check for DTCs (Click here).

    OK :
    DTC B1446/46 is not output.


NG
REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY (Click here)
OK

USE SIMULATION METHOD TO CHECK (Click here)