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

Heater & Air Conditioning System. Lexus Is250, Is220D. Gse20 Ale20
Air Conditioning. Lexus Is250, Is220D. Gse20 Ale20

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

READ VALUE OF INTELLIGENT TESTER

REPLACE AIR MIX CONTROL SERVO MOTOR

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


DESCRIPTION

The air mix damper servo sends pulse signals to inform the air conditioner amplifier of the damper position. The air conditioner amplifier activates the motor (normal, reverse) based on the signals to move the air mix damper (driver seat) 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 seat side is controlled.
HINT:
Confirm that no mechanical problem is present because this diagnostic code can be output when either a damper link or 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 conditioner amplifier operates air mix control servo motor
  1. Air mix control servo motor
  2. Air conditioning harness
  3. Air amplifier

WIRING DIAGRAM


Lexus Is250, Is220D. Gse20 Ale20.Air Conditioning.Air Conditioning System. Dtc B1446/46 Air Mix Damper Control Servo Motor Circuit (Driver Side)


INSPECTION PROCEDURE

1.READ VALUE OF INTELLIGENT TESTER

  1. Connect the intelligent tester to the DLC3.

  1. Turn the engine switch on (IG) and turn the intelligent tester main switch on.

  1. Operate the driver side temperature adjustment switch.

  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
Air Mix Servo Targ Pulse (D)
(Air Mix Pulse-D)
Driver side air mix servo motor target pulse / Min.: 0, Max.: 255
MAX. COLD: 5 (pulse)
MAX. HOT: 104 (pulse)
-
OK:
The display is as specified in the normal condition column.

Result:

Result
Proceed to
NG
A
OK (When troubleshooting according to the PROBLEM SYMPTOMS TABLE)
B
OK (When troubleshooting according to the DTC)
C


B
PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

C
REPLACE AIR CONDITIONING AMPLIFIER
A


2.REPLACE AIR MIX CONTROL SERVO MOTOR
HINT:
Since the servo motor cannot be inspected while it is removed from the vehicle, replace the servo motor with a normal one and check that the condition returns to normal.

  1. Check for DTCs.

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


B
END
A

REPLACE AIR CONDITIONING HARNESS