Nissan Altima L32. Manual - part 816

HAC-38

< COMPONENT DIAGNOSIS >

[AUTOMATIC AIR CONDITIONER]

INTAKE DOOR MOTOR

The intake door motor (1) is attached to the blower unit. It rotates so

that air is drawn from inlets set by the front air control. Motor rotation

is conveyed to a lever which activates the intake door.

Diagnosis Procedure

INFOID:0000000004498208

SYMPTOM:

• Intake door does not change.

• Intake door motor does not operate normally.

INSPECTION FLOW

1.

 CONFIRM SYMPTOM BY PERFORMING OPERATION CHECK - REC (

)

1. Press the vent mode.(

). 

2. Press REC (

) switch. The REC (

) indicator should illumination.

3. Press REC (

) switch again. The REC (

) indicator should go out.

4. Listen for intake door position change (you should sound change slightly).
Can a symptom be duplicated?

YES

>> GO TO 3

 NO

>> GO TO 2

2.

 PERFORM COMPLETE OPERATIONAL CHECK

Perform a complete operational check and check for any symptoms. Refer to 

HAC-5, "Description and Condi-

tions"

.

Is the inspection result normal?

YES

>> Refer to 

HAC-83, "Symptom Matrix Chart"

.

NO

>> System OK.

3.

 CHECK FOR SERVICE BULLETINS

Check for any service bulletins.

>> GO TO 4

4.

 CHECK INTAKE DOOR MOTOR OPERATION

Check and verify intake door mechanism for smooth operation.
Is the inspection result normal?

YES

>> GO TO 5

NO

>> Repair as necessary.

5.

 CHECK LAN SYSTEM CIRCUIT

Perform diagnostic procedure for the LAN system. Refer to 

HAC-28, "Diagnosis Procedure"

.

Is the inspection result normal?

YES

>> GO TO 6

NO

>> Repair as necessary. 

6.

 CHECK AMBIENT SENSOR CIRCUIT

Perform diagnostic procedure for the mode door motor. Refer to 

HAC-32, "Diagnosis Procedure"

.

Is the inspection result normal?

YES

>> GO TO 7

NO

>> Repair as necessary.

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INTAKE DOOR MOTOR

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[AUTOMATIC AIR CONDITIONER]

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7.

 CHECK IN-VEHICLE SENSOR CIRCUIT

Perform diagnostic procedure for the in-vehicle sensor circuit. Refer to 

HAC-53, "Diagnosis Procedure"

.

Is the inspection result normal?

YES

>> GO TO 8

NO

>> Repair as necessary.

8.

 CHECK SUNLOAD SENSOR CIRCUIT

Perform diagnostic procedure for the sunload sensor circuit. Refer to 

HAC-56, "Diagnosis Procedure"

.

Is the inspection result normal?

YES

>> GO TO 9

NO

>> Repair as necessary.

9.

 CHECK INTAKE SENSOR CIRCUIT

Perform diagnostic procedure for the intake sensor circuit. Refer to 

HAC-59, "Diagnosis Procedure"

.

Is the inspection result normal?

YES

>> GO TO 10

NO

>> Repair as necessary.

10.

 CHECK AIR MIX DOOR MOTORS PBR CIRCUIT

Perform diagnostic procedure for the intake sensor circuit. Refer to 

HAC-35, "Diagnosis Procedure"

.

Is the inspection result normal?

YES

>> GO TO 11

NO

>> Repair as necessary.

11.

 RECHECK FOR SYMPTOMS 

Perform a complete operational check and check for any symptoms. Refer to 

HAC-5, "Description and Condi-

tions"

.

Does another symptom exist?

YES

>> Repair as necessary.

NO

>> Replace front air control. Refer to 

VTL-8, "Removal and Installation"

.

DIAGNOSIS PROCEDURE FOR INTAKE DOOR MOTOR

SYMPTOM: Intake door motor does not operate normally.

Perform diagnosis procedure. Refer to 

HAC-28, "Diagnosis Procedure"

.

HAC-40

< COMPONENT DIAGNOSIS >

[AUTOMATIC AIR CONDITIONER]

BLOWER MOTOR

BLOWER MOTOR

Description

INFOID:0000000004498209

SYSTEM DESCRIPTION

Component Parts

Fan speed control system components are:

• Front air control

• A/C LAN system (PBR built-in mode door motor, air mix door motors and intake door motor)

• In-vehicle sensor

• Ambient sensor

• Sunload sensor

• Intake sensor

• Fan control amp.

System Operation

Automatic Mode

In the automatic mode, the blower motor speed is calculated by the front air control based on the input from

the PBR, in-vehicle sensor, sunload sensor, intake sensor and ambient sensor.

When the air flow is increased, the duty ratio of the blower fan motor’s drive signal is changed at 8%/sec. to

prevent a sudden increase in air flow.

In addition to manual air flow control and the usual automatic air flow control, starting air flow control, low

water temperature starting control and high passenger compartment temperature starting control are avail-

able.

Starting Fan Speed Control

Start up from COLD SOAK Condition (Automatic mode)

In a cold start up condition where the engine coolant temperature is below 56

°C (133°F), the blower will not

operate for a short period of time (up to 150 seconds). The exact start delay time varies depending on the

ambient and engine coolant temperature.

In the most extreme case (very low ambient) the blower starting delay will be 150 seconds as described

above. After this delay, the blower will operate at low speed until the engine coolant temperature rises above

56

°C (133°F), at which time the blower speed will increase to the objective speed.

Start up from usual or HOT SOAK Condition (Automatic mode)

The blower will begin operation momentarily after the AUTO switch is pressed. The blower speed will gradu-

ally rise to the objective speed over a time period of 3 seconds or less (actual time depends on the objective

blower speed).

Blower Speed Compensation

Sunload

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BLOWER MOTOR

HAC-41

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When the in-vehicle temperature and the set temperature are very close, the blower will be operating at low

speed. The low speed will vary depending on the sunload. During conditions of low or no sunload, the blower

speed is at duty ratio 25%. During high sunload conditions, the front air control. raise the blower speed (duty

ratio 49%).

Blower Speed Control Specification

Component Function Check

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INSPECTION FLOW

1.

 CONFIRM SYMPTOM BY PERFORMING OPERATION CHECK - FRONT BLOWER

1. Rotate the blower control dial clockwise. Blower should operate. 

2. Rotate the blower control dial clockwise, and continue checking blower speed until all speeds are

checked.

Can a symptom be duplicated?

YES

>> GO TO 3

 NO

>> GO TO 2

2.

 PERFORM COMPLETE OPERATIONAL CHECK

Perform a complete operational check and check for any symptoms. Refer to 

HAC-83,

"Symptom Matrix Chart"

.

Is the inspection result normal?

YES

>> Refer to 

HAC-83, "Symptom Matrix Chart"

.

NO

>> System OK. 

3.

 CHECK FOR SERVICE BULLETINS

Check for any service bulletins.

>> GO TO 4

4.

 CHECK ENGINE COOLANT TEMPERATURE.

Check engine coolant temperature.
Is engine coolant temperature below 56

°C (133°F)?

YES

>> GO TO 5

 NO

>> Blower motor operation is normal.

5.

 CHECK BLOWER MOTOR STARTING SPEED.

Check blower motor starting blower speed control.
Is blower motor operation under starting blower speed control?

YES

>> GO TO 6

 NO

>> Check blower motor circuit. Refer to 

HAC-42, "Diagnosis Procedure"

.

6.

 CHECK AMBIENT SENSOR CIRCUIT

Perform diagnostic procedure for the mode door motor. Refer to

HAC-32, "Diagnosis Procedure"

.

Is the inspection result normal?

YES

>> GO TO 7

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