Nissan Tiida C11. Manual - part 892

HAC-232

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[AUTO AIR CONDITIONER (W/NAVI)]

BLOWER MOTOR CONTROL SYSTEM

BLOWER MOTOR CONTROL SYSTEM

System Description

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SYSTEM DESCRIPTION

Component Parts

Blower motor speed control system components are:

• Front air control
• In-vehicle sensor
• Ambient sensor
• Sunload sensor
• Intake sensor

System Operation

Automatic Mode

In the automatic mode, the blower motor speed is calculated by the front air control based on input from in-
vehicle sensor, sunload sensor, intake sensor and ambient sensor. 
The blower motor is applied voltage ranges from approximately 3.0 volts (lowest speed) to 12 volts (highest
speed).
The control blower speed (in the range of 3.0 to 12V), front air control supplies a gate voltage to the power
transistor. Based on this voltage, front air control controls voltage supplied to the blower motor.

Starting Blower Motor 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, 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, 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 A/C switch is pushed. The blower speed will gradually
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
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

AWIIA0341GB

BLOWER MOTOR CONTROL SYSTEM

HAC-233

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[AUTO AIR CONDITIONER (W/NAVI)]

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low speed is usual low speed (approx. 4.0V). During high sunload conditions, the front air control causes the
blower motor speed to increase (approx. 6.5V).

Blower Motor Speed Control Specification

Front Blower Motor Component Function Check

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INSPECTION FLOW

1.

CONFIRM SYMPTOM BY PERFORMING OPERATIONAL CHECK - FRONT BLOWER

1.

Turn the blower control dial. Blower motor should operate.

2.

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

Can the 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-202, "Operational Check"

.

Can a symptom be duplicated?

YES

>> Refer to 

HAC-201, "How to Perform Trouble Diagnosis For Quick And Accurate Repair"

.

NO

>> System OK.

3.

CHECK FOR SERVICE BULLETINS

Check for any service bulletins.

>> GO TO 4.

4.

PERFORM SELF-DIAGNOSIS.

Set in Self-diagnostic mode. Refer to 

HAC-213, "Front Air Control Self-Diagnosis"

.

Are any self-diagnosis codes present?

YES

>> Repair as necessary.

NO

>> GO TO 5.

5.

 CHECK AMBIENT SENSOR CIRCUIT

Perform diagnostic procedure for the ambient sensor circuit. Refer to 

HAC-244, "Ambient Sensor Diagnosis

Procedure"

.

YES or NO

YES

>> GO TO 6.

NO

>> Repair as necessary.

6.

 CHECK IN-VEHICLE SENSOR CIRCUIT

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

HAC-247, "In-Vehicle Sensor Diagno-

sis Procedure"

.

YES or NO

YES

>> GO TO 7.

NO

>> Repair as necessary.

AWIIA0297GB

HAC-234

< COMPONENT DIAGNOSIS >

[AUTO AIR CONDITIONER (W/NAVI)]

BLOWER MOTOR CONTROL SYSTEM

7.

 CHECK SUNLOAD SENSOR CIRCUIT

Perform diagnostic procedure for the sunload sensor circuit. Refer to 

HAC-250, "Sunload Sensor Diagnosis

Procedure"

.

YES or NO

YES

>> GO TO 8.

NO

>> Repair as necessary.

8.

 CHECK INTAKE SENSOR CIRCUIT

Perform diagnostic procedure for the intake sensor circuit. Refer to 

HAC-253, "Intake Sensor Diagnosis Pro-

cedure"

.

YES or NO

YES

>> GO TO 9.

NO

>> Repair as necessary.

9.

 RECHECK FOR SYMPTOMS 

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

HAC-202, "Operational Check"

.

Does another symptom exist?

YES

>> Repair as necessary.

NO

>> Replace front air control. Refer to XXXX.

Front Blower Motor Diagnosis Procedure

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SYMPTOM: Front blower motor operation is malfunctioning.

DIAGNOSTIC PROCEDURE FOR BLOWER MOTOR

SYMPTOM: Front blower motor operation is malfunctioning.

1.

CHECK POWER SUPPLY FOR FRONT BLOWER MOTOR

1.

Disconnect front blower motor connector.

2.

Turn ignition switch ON.

3.

Rotate blower control dial to maximum speed.

4.

Check voltage between front blower motor harness connector
M62 terminal 1 and ground.

Is the inspection result normal

YES

>> GO TO 2.

NO

>>

Check power supply circuit and 15A fuses (Nos. 15 and 17), located in the fuse block.

• If fuses are OK, check harness for open circuit. Repair or replace if necessary.
• If fuses are NG, replace fuse and check harness for short circuit. Repair or replace if necessary.

2.

CHECK CIRCUIT POWER SUPPLY FOR VARIABLE BLOWER CONTROL

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Terminals

Voltage

(Approx.)

(+)

(

−

)

Connector

Terminal 

Ground

Front blower mo-

tor: M62

1

Battery voltage

SJIA0794E

BLOWER MOTOR CONTROL SYSTEM

HAC-235

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1.

Turn ignition switch OFF.

2.

Connect front blower motor connector.

3.

Disconnect variable blower control connector.

4.

Turn ignition switch ON.

5.

Check voltage between variable blower control harness connec-
tors M91 (A) terminal 1, and M90 (B) terminal 6 and ground.

Is the inspection result normal

YES

>> GO TO 3.

NO

>> • Terminal 1 - Ground: Repair harness or connector.

• Terminal 6 - Ground: GO TO 5.

3.

CHECK GROUND CIRCUIT FOR VARIABLE BLOWER CONTROL

1.

Turn ignition switch OFF.

2.

Check continuity between variable blower control harness con-
nector M91 terminal 2 and ground.

Is the inspection result normal

YES

>> GO TO 4.

NO

>> Repair harness or connector.

4.

CHECK BLOWER MOTOR

1.

Disconnect front blower motor connector.

2.

Check continuity between front blower motor terminals.

Is the inspection result normal

YES

>> GO TO 5.

NO

>> Replace blower motor. Refer to XXXX.

5.

CHECK CIRCUIT CONTINUITY BETWEEN FRONT BLOWER MOTOR AND VARIABLE BLOWER CON-

TROL

Check continuity between front blower motor harness connector
M62 (A) terminal 2 and variable blower control harness connector
M90 (B) terminal 6. 

Is the inspection result normal

Terminals

Voltage

(Approx.)

(+)

(

−

)

Connector

Terminal 

Ground

Variable blower control: M91

1

Battery voltage

Variable blower control: M90

6

Ground

Battery voltage

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Connector

Terminal

Ground

Continuity

Variable blower control: 

M91

2

Yes

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Terminals

Continuity

1

2

Yes

SJIA0798E

A

B

Continuity

Connector

Terminal

Connector

Terminal

Front blower mo-

tor: M62

2

Variable blower 

control: M90

6

Yes

AWIIA0302ZZ