Nissan Altima (L32) 2007-2012 Service Manual: Air mix door motor

Description

SYSTEM DESCRIPTION

Component Parts

Air mix door control system components are: • Front air control

• Air mix door motor (LCU)

System Operation

The front air control receives user inputs through its various dials and switches. 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.

COMPONENT DESCRIPTION

Air Mix Door Motor

The air mix door motor (1) is attached to the heater & cooling unit assembly. It rotates so that the air mix door is opened or closed to a position set by the front air control. Motor rotation is then conveyed through a shaft and the air mix door position feedback is then sent to the front air control by PBR built-in air mix door motor.

Diagnosis Procedure

SYMPTOM: • Discharge air temperature does not change.

• Air mix door motor does not operate.

INSPECTION FLOW

1. CONFIRM SYMPTOM BY PERFORMING OPERATION CHECK - TEMPERATURE INCREASE

1. Turn the temperature control dial clockwise to maximum heat.

2. Check for hot air at discharge air outlets.

>> GO TO 2

2. CONFIRM SYMPTOM BY PERFORMING OPERATION CHECK - TEMPERATURE DECREASE

1. Turn the temperature control dial counterclockwise to maximum cold.

2. Check for cold air at discharge air outlets.

Can a symptom be duplicated? YES >> GO TO 4

NO >> GO TO 3

3. PERFORM COMPLETE OPERATIONAL CHECK

Perform a complete operational check and check for any symptoms. Refer to HAC-102, "Operational Check".

Is the inspection result normal? YES >> Refer to HAC-155, "Symptom Matrix Chart".

NO >> System OK.

4. CHECK FOR SERVICE BULLETINS

Check for any service bulletins.

>> GO TO 5

5. CHECK AIR MIX DOOR MOTOR OPERATION

Check and verify air mix door mechanism for smooth operation.

Is the inspection result normal? YES >> GO TO 6

NO >> Repair as necessary.

6. CHECK LAN SYSTEM CIRCUIT

Perform diagnostic procedure for the LAN system. Refer to HAC-115, "Diagnosis Procedure".

Is the inspection result normal? YES >> GO TO 7

NO >> Repair as necessary.

7. CHECK AIR MIX DOOR MOTOR PBR CIRCUIT

Perform diagnostic procedure for the intake sensor circuit. Refer to HAC-122, "Diagnosis Procedure".

Is the inspection result normal? YES >> GO TO 8

NO >> Repair as necessary.

8. RECHECK FOR SYMPTOMS

Perform a complete operational check and check for any symptoms. Refer to HAC-102, "Operational Check".

Does another symptom exist? YES >> Repair as necessary.

NO >> Replace front air control. Refer to VTL-8, "Removal and Installation".

DIAGNOSIS PROCEDURE FOR AIR MIX DOOR MOTOR

SYMPTOM: Discharge air temperature does not change.

Perform diagnosis procedure. Refer to HAC-115, "Diagnosis Procedure".