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

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

DESCRIPTION

The air mix control servo motor (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 the signals to move the air mix damper (for driver side) to any position. As a result, the air mix damper (for driver side) varies the mixture of hot air from the heater core and cold air from the evaporator so that the temperature of the air blowing toward the front passenger side is as requested.

Tip:

Confirm that no mechanical problem is present because this trouble code can be stored 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 control servo motor (for driver side).	Air mix control servo motor (for driver side) Air conditioning harness assembly Air conditioning amplifier assembly

WIRING DIAGRAM

PROCEDURE

CHECK FOR DTC

Clear the DTCs (Click here).

Check for DTCs (Click here).

Table 1. Result
Result	Proceed to
DTC B1446/46 is not output	A
DTC B1446/46 is output	B
DTC B1446/46 and B1497/97 are output	C

USE SIMULATION METHOD TO CHECK

(Click here)

GO TO DTC B1497/97

(Click here)

READ VALUE USING INTELLIGENT TESTER

Use the Data List to check if the servo motor is functioning properly.

Table 2. Air Conditioner
Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
Air Mix Servo Targ Pulse (D)	Air mix control servo motor (for driver side) target pulse / Min.: 0, Max.: 255	for LHD: 92 (pulse): MAX COOL 5 (pulse): MAX HOT for RHD: 6 (pulse): MAX COOL 93 (pulse): MAX HOT	-
Air Mix Servo Actual Pulse (D)	Air mix control servo motor (for driver side) actual pulse / Min.: 0, Max.: 255	for LHD: 92 (pulse): MAX COOL 5 (pulse): MAX HOT for RHD: 6 (pulse): MAX COOL 93 (pulse): MAX HOT	-

The display is as specified in the normal condition column.

Table 3. Result
Result	Proceed to
OK (When troubleshooting according to the DTC)	A
OK (When troubleshooting according to Problem Symptoms Table)	B
Both target pulse and actual pulse do not display	C
Target pulse displays normally, but actual pulse does not display	D

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

(Click here)

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY

(Click here)

CHECK AIR MIX CONTROL SERVO MOTOR (FOR DRIVER SIDE)Click here

CHECK FOR DTC
1. Clear the DTCs (Click here).
2. Check for DTCs (Click here).
  
  OK
  
  DTC B1446 is not output.
USE SIMULATION METHOD TO CHECK

(Click here)

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY

(Click here)
CHECK AIR MIX CONTROL SERVO MOTOR (FOR DRIVER SIDE)
1. Replace the air mix control servo motor (for driver side) (Click here).
  
  Tip:
  Since the air mix control servo motor cannot be inspected while it is removed from the vehicle, replace the air mix control servo motor with a new or normally functioning one.
2. Clear the DTCs (Click here).
3. Check for DTCs (Click here).
  
  OK
  
  DTC B1446 is not output.
END (AIR MIX CONTROL SERVO MOTOR [FOR DRIVER SIDE] IS FAULTY)
CHECK AIR CONDITIONING HARNESS ASSEMBLY
1. Temporarily replace the air conditioning harness assembly with a new or normally functioning one (Click here).
2. Clear the DTCs (Click here).
3. Check for DTCs (Click here).
  
  OK
  
  DTC B1446 is not output.
END (AIR CONDITIONING HARNESS ASSEMBLY IS FAULTY)

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY

(Click here)