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DTC    B1442/42    Air Inlet Damper Control Servo Motor Circuit

for Preparation Click here


DESCRIPTION

The air inlet control servo motor sends pulse signals to indicate the damper position to the A/C amplifier. The A/C amplifier activates the motor (normal or reverse) based on these signals to move the air inlet mode selection air inlet control damper to any position, which controls the intake air settings (FRESH, FRESH/RECIRCULATION and RECIRCULATION).
The A/C amplifier communicates with the servo through a communication/driver IC and wiring assembly called the air conditioning harness.

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
B1442/42
Air inlet damper position sensor value does not change even if A/C amplifier operates air inlet control servo motor
  1. Air inlet control servo motor
  2. Air conditioning harness
  3. A/C amplifier

WIRING DIAGRAM


E178937E16


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 R/F (Recirculation/Fresh) 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 Inlet Damper Targ Pulse
    		Air inlet servo motor target pulse / Min.: 0, Max.: 255
    for LHD:
    1. RECIRCULATION: 19 (pulse)
    2. FRESH: 7 (pulse)
    for RHD:
    1. RECIRCULATION: 7 (pulse)
    2. FRESH: 25 (pulse)
    		-
    Air Inlet Damper Actual Pulse
    		Air inlet servo motor actual pulse / Min.: 0, Max.: 255
    for LHD:
    1. RECIRCULATION: 19 (pulse)
    2. FRESH: 7 (pulse)
    for RHD:
    1. RECIRCULATION: 7 (pulse)
    2. FRESH: 25 (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 A/C AMPLIFIER (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 Inlet Damper Targ Pulse
    		Air inlet damper target pulse
    		Min.: 0, Max.: 255
    		-

    OK:
    Recirculation damper position changes in accordance with each control range.



NG
Go to step 3
OK

REPLACE A/C AMPLIFIER (Click here)  

3.INSPECT AIR INLET CONTROL SERVO MOTOR

  1. Replace the air inlet control servo motor (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 B1442/42 is output
    		A
    DTC B1442/42 is not output
    		B



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


4.INSPECT AIR CONDITIONING HARNESS

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

    HINT:
    Since the air conditioning harness cannot be inspected while it is removed from the vehicle, replace the air conditioning harness 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 B1442/42 is output
    		A
    DTC B1442/42 is not output
    		B



B
END (AIR CONDITIONING HARNESS WAS DEFECTIVE)
A

REPLACE A/C AMPLIFIER (Click here)