Your Vehicle: 2009 Nissan-Datsun Altima V6-3.5L (VQ35DE)
 
Vehicle » Heating and Air Conditioning » Testing and Inspection » Component Tests and General Diagnostics » Mode Door » Automatic Air Conditioner  
 
 
  Automatic Air Conditioner  
 

MODE DOOR MOTOR

Description

SYSTEM DESCRIPTION

Component Parts

Mode door control system components are:

  • Front air control
  • Mode door motor (LCU)
  • In-vehicle sensor
  • Ambient sensor
  • Sunload sensor
  • Intake sensor

System Operation
The front air control receives data from each of the sensors. The front air control sends air mix door, mode door and intake door opening angle data to the air mix door motor LCU, mode door motor LCU and intake door motor LCU.
The air mix door motor, mode door motor and intake door motor read their respective signals according to the address signal. Opening angle indication signals received from the front air control and each of the motor position sensors are compared by the LCU's in each motor with the existing decision and opening angles. Subsequently, HOT/COLD or DEFROST/VENT or FRESH/RECIRCULATION operation is selected. The new selection data is returned to the front air control.

  

Mode Door Control Specification

  

COMPONENT DESCRIPTION

Mode Door Motor

  

The mode door motor (1) is attached to the heater and cooling unit assembly. It rotates so that air is discharged from the outlet set by the front air control. Motor rotation is conveyed to a link which activates the mode door.

MODE DOOR MOTOR

Diagnosis Procedure

SYMPTOM: Mode door motor and/or air mix door motor does not operate normally.
Perform diagnostic procedure for LAN system circuit. Refer to See: LAN System Circuit\Automatic Air Conditioner.

SYMPTOM:

  • Air outlet does not change.
  • Mode door motor does not operate normally.

Inspection FLOW

  1. CONFIRM SYMPTOM BY PERFORMING OPERATION CHECK - DISCHARGE AIR

  

  1. Press each of the four mode position switches and then press the (DEF) switch. Each position indicator should illuminate.
  2. Confirm that discharge air comes out according to the air distribution table. Refer to See: Description and Operation\Automatic Air Conditioner\System Description.

  

NOTE:
Confirm that the A/C compressor clutch is engaged (visual Inspection and intake door position is at (FRESH) when (DEF) or (D/F) is selected.
Can a symptom be duplicated?
YES >> GO TO 3
NO >> GO TO 2

  1. PERFORM COMPLETE OPERATIONAL CHECK Perform a complete operational check and check for any symptoms. Refer to See: Initial Inspection and Diagnostic Overview\Inspection And Adjustment\Description And Conditions\Automatic Air Conditioner.

Can a symptom be duplicated?
YES >> Refer to See: Symptom Related Diagnostic Procedures\Automatic Air Conditioner System\Symptom Matrix Chart.
NO >> System OK.

  1. CHECK FOR SERVICE BULLETINS Check for any service bulletins.

>> GO TO 4

  1. CHECK LAN SYSTEM CIRCUIT Perform diagnostic procedure for the LAN system. Refer to See: LAN System Circuit\Automatic Air Conditioner.

Is the Inspection result normal?
YES >> GO TO 5
NO >> Repair as necessary.

  1. CHECK MODE DOOR OPERATION Check and verify mode door mechanism for smooth operation in each mode.

Is the Inspection result normal?
YES >> GO TO 6
NO >> Repair as necessary.

  1. CHECK AMBIENT SENSOR CIRCUIT Perform diagnostic procedure for the mode door motor. Refer to "Diagnosis Procedure".

Is the Inspection result normal?
YES >> GO TO 7
NO >> Repair as necessary.

  1. CHECK IN-VEHICLE SENSOR CIRCUIT Perform diagnostic procedure for the in-vehicle sensor circuit. Refer to See: In-Vehicle Sensor\Diagnosis Procedure.

Is the Inspection result normal?
YES >> GO TO 8
NO >> Repair as necessary.

  1. CHECK SUNLOAD SENSOR CIRCUIT Perform diagnostic procedure for the sunload sensor circuit. Refer to See: Sunload Sensor\Diagnosis Procedure.

Is the Inspection result normal?
YES >> GO TO 9
NO >> Repair as necessary.

  1. CHECK INTAKE SENSOR CIRCUIT Perform diagnostic procedure for the intake sensor circuit. Refer to See: Intake Sensor\Diagnosis Procedure.

Is the Inspection result normal?
YES >> GO TO 10
NO >> Repair as necessary.

  1. CHECK AIR MIX DOOR MOTOR PBR CIRCUIT Perform diagnostic procedure for the intake sensor circuit. Refer to See: Air Mix Door\Automatic Air Conditioner.

Is the Inspection result normal?
YES >> GO TO 11
NO >> Repair as necessary.

  1. RECHECK FOR SYMPTOMS Perform a complete operational check and check for any symptoms. Refer to See: Initial Inspection and Diagnostic Overview\Inspection And Adjustment\Description And Conditions\Automatic Air Conditioner.

Does another symptom exist?
YES >> Repair as necessary.
NO >> Replace front air control. Refer to See: Control Module HVAC\Service and Repair.

DIAGNOSIS PROCEDURE FOR MODE DOOR MOTOR
SYMPTOM: Mode door motor does not operate normally.
Perform diagnosis procedure. Refer to See: LAN System Circuit\Automatic Air Conditioner.