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

for Preparation Click here


DESCRIPTION

The air mix control servomotor (air mix damper servo sub-assembly) is controlled by the A/C amplifier assembly.
The air mix control servomotor moves the air mix damper by rotating (normal, reverse) the motor with electrical power from the A/C amplifier assembly.
This adjusts the mix ratio of the air that passes through the evaporator and heater core and controls the air flow temperature. Air flow temperature changes when moving the air mix damper to the target point. The target point can be detected with the air mix damper position sensor.

DTC No.
DTC Detecting Condition
Trouble Area
B1446/46
Air mix damper position sensor value does not change even if air conditioning amplifier assembly operates air mix servomotor.
  1. Air mix control servomotor
  2. Harness or connector between air mix control servomotor and A/C amplifier assembly
  3. A/C amplifier assembly

WIRING DIAGRAM


I036322E11


INSPECTION PROCEDURE

1.READ VALUE OF INTELLIGENT TESTER

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch ON and push the intelligent tester main switch on.

  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
A/M DAMP POS-D
Air mix damper position (Driver side) / min.: -14% max.: 113.5%
Damper is at "MAX. COOL": -5%
Damper is at "MAX. HOT": 105%
-
A/M DAMP TARG-D
Air mix damper target position (Driver side) / min.: -14% max.: 113.5%

OK:
When the target position is at the "MAX. COOL" (-5%), the actual opening angle is 19.0% or less.
When the target position is at the "MAX. HOT" (105%), the actual opening angle is 81.0% or more.


Result:

Result
Proceed to
NG
A
OK (Checking from the PROBLEM SYMPTOM TABLE)
B
OK (Checking from the DTC)
C



B
PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

C
REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY
A


2.PERFORM ACTIVE TEST BY INTELLIGENT TESTER

  1. Connect the intelligent tester to the DLC3.

  1. Turn the ignition switch ON and push the intelligent tester main switch on.

  1. Select the item below in the ACTIVE TEST and then check the air flow temperature by hand.

    ACTIVE TEST / AIR CONDITIONER 
    Item
    		Test Details/Display
    (Range)
    		Diagnostic Note
    AIR MIX DAMP-D
    		Air mix damper (Driver side) /min.: -14% max.: 113.5%
    		-

    OK:
    When the lever is moved to the "MAX. HOT" side, warm air comes out.
    When the lever is moved to the "MAX. COOL" side, cool air comes out.


Result:

Result
Proceed to
NG
A
OK (Checking from the PROBLEM SYMPTOM TABLE)
B
OK (Checking from the DTC)
C



B
PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

C
REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY
A


3.PERFORM ACTUATOR CHECK

  1. Set the actuator check mode (Click here).

  1. Press the DEF switch and change to the step operation.

  1. Check the air flow temperature by hand.


Display Code
Air Mix Damper Operation
0
"COOL" side (-5%)
1
"COOL" side (-5%)
2
"COOL" side (-5%)
3
"COOL" side (-5%)
4
"COOL"/"HOT" (50% opened)
5
"COOL"/"HOT" (50% opened)
6
"COOL"/"HOT" (50% opened)
7
"HOT" side (105%)
8
"HOT" side (105%)
9
"HOT" side (105%)

OK:
Air flow temperature changes in accordance with each display code.


Result:

Result
Proceed to
NG
A
OK (Checking from the PROBLEM SYMPTOM TABLE)
B
OK (Checking from the DTC)
C



B
PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

C
REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY
A


4.INSPECT AIR MIX CONTROL SERVOMOTOR


    E110736E01

  1. Remove the air mix control servomotor.

  1. Disconnect the connector from the air mix control servomotor.

  1. Connect the positive (+) lead from the battery to terminal 5 and the negative (-) lead to terminal 4, then check that the lever turns to the "MAX. HOT" position smoothly.

    OK:
    Lever turns to "MAX. HOT" position smoothly.

  1. Connect the positive (+) lead from the battery to terminal 4 and the negative (-) lead to terminal 5, then check that the lever turns to the "MAX. COOL" position smoothly.

    OK:
    Lever turns to "MAX. COOL" position smoothly.



NG
REPLACE AIR MIX CONTROL SERVOMOTOR
OK


5.CHECK HARNESS AND CONNECTOR (AIR MIX CONTROL SERVOMOTOR - A/C AMPLIFIER ASSEMBLY)


    E109216E24

  1. Disconnect the connector from the A/C amplifier assembly.

  1. Measure the resistance according to the value(s) in the table below.

    Resistance:
    Tester connection
    (Symbols)
    		Condition
    		Specified condition
    A10-14 (AMDC) - A20-4 (MCOOL)
    		Always
    		Below 1 Ω
    A10-15 (AMDH) - A20-5 (MHOT)
    		Always
    		Below 1 Ω
    A10-14 (AMDC) - Body ground
    		Always
    		10 kΩ or higher
    A10-15 (AMDH) - Body ground
    		Always
    		10 kΩ or higher



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY