Nissan Titan. Manual - part 385

BLOWER MOTOR CONTROL SYSTEM

HAC-45

< DTC/CIRCUIT DIAGNOSIS >

[AUTOMATIC AIR CONDITIONER]

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SYMPTOM: Blower motor operation is malfunctioning under starting

blower speed control.

1.

CHECK FUSES

Check 20A fuses [No. 24 and 27 (Located in the fuse and fusible link box)]. For fuse layout. Refer to 

PG-77,

"Terminal Arrangement"

.

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> GO TO 9.

2.

CHECK FRONT BLOWER MOTOR POWER SUPPLY CIRCUIT 

1. Turn ignition switch OFF.

2. Disconnect front blower motor connector.

3. Turn ignition switch ON.

4. Press the A/C switch.

5. Rotate blower control dial to maximum speed.

6. Check voltage between front blower motor harness connector

M62 terminal 2 and ground.

Is the inspection result normal?

YES

>> GO TO 11.

NO

>> GO TO 3.

3.

CHECK FRONT BLOWER MOTOR RELAY (SWITCH SIDE) POWER SUPPLY CIRCUIT

1. Turn ignition switch OFF.

2. Disconnect front blower motor relay.

3. Check voltage between front blower motor relay harness con-

nector M107 terminal 5 and ground.

Is the inspection result normal?

YES

>> GO TO 4.

NO

>> Repair harness or connector.

AWIIA1115GB

Fuses are good.

2 - Ground

: Battery voltage

WJIA1331E

5 - Ground

: Battery voltage

WJIA1886E

HAC-46

< DTC/CIRCUIT DIAGNOSIS >

[AUTOMATIC AIR CONDITIONER]

BLOWER MOTOR CONTROL SYSTEM

4.

CHECK FRONT BLOWER MOTOR RELAY

Turn ignition switch OFF.

Check front blower motor relay. Refer to 

HAC-48, "Front Blower Motor Component Inspection"

.

Is the inspection result normal?

YES

>> GO TO 5.

NO

>> Replace front blower motor relay.

5.

CHECK FRONT BLOWER MOTOR RELAY (SWITCH SIDE) CIRCUIT FOR OPEN

Check continuity between front blower motor relay harness connec-

tor M107 terminal 3 and front blower motor harness connector M62

terminal 2.

Is the inspection result normal?

YES

>> GO TO 6.

NO

>> Repair harness or connector.

6.

CHECK VARIABLE BLOWER CONTROL POWER SUPPLY CIRCUIT FOR OPEN

1. Disconnect variable blower control harness connector.

2. Check continuity between front blower motor relay harness con-

nector M107 (A) terminals 3 and variable blower control harness

connector M122 (B) terminal 4.

Is the inspection result normal?

YES

>> GO TO 7.

NO

>> Repair harness or connector.

7.

CHECK VARIABLE BLOWER CONTROL SIGNAL CIRCUIT

1. Disconnect front air control connector.

2. Check continuity between front air control harness connector

M49 (B) terminal 13 and variable blower control harness con-

nector M122 (A) terminal 3.

Is the inspection result normal?

YES

>> GO TO 8.

NO

>> Repair harness or connector.

8.

CHECK FRONT BLOWER MOTOR RELAY (COIL SIDE) POWER SUPPLY

1. Turn ignition switch ON.

2. Check voltage between front blower motor relay harness con-

nector M107 terminal 2 and ground.

Is the inspection result normal?

YES

>> GO TO 9.

NO

>> Repair front blower motor ground circuit or connector.

3 - 2

: Continuity should exist.

WJIA1360E

3 - 4

: Continuity should exist.

AWIIA0175ZZ

13 - 3

: Continuity should exist.

AWIIA0413ZZ

2 - Ground

: Battery voltage

AWIIA1386ZZ

BLOWER MOTOR CONTROL SYSTEM

HAC-47

< DTC/CIRCUIT DIAGNOSIS >

[AUTOMATIC AIR CONDITIONER]

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9.

REPLACE FUSES

1. Replace fuses.

2. Activate the front blower motor.
Does the fuse blow?

YES

>> GO TO 10.

NO

>> Inspection End.

10.

CHECK FRONT BLOWER MOTOR POWER SUPPLY CIRCUIT FOR SHORT

1. Turn ignition switch OFF.

2. Disconnect front blower motor connector and variable blower

control connector.

3. Check continuity between variable blower control harness con-

nector M122 terminal 4 and ground.

Is the inspection result normal?

YES

>> GO TO 11.

NO

>> Repair harness or connector.

11.

CHECK VARIABLE BLOWER CONTROL SIGNAL CIRCUIT

1. Disconnect front air control connector.

2. Check continuity between front air control harness connector

M49 (B) terminal 13 and variable blower control harness con-

nector M122 (A) terminal 3.

Is the inspection result normal?

YES

>> GO TO 12.

NO

>> Repair harness or connector.

12.

CHECK FRONT BLOWER MOTOR

Check front blower motor. Refer to 

HAC-48, "Front Blower Motor Component Inspection"

.

Is the inspection result normal?

YES

>> GO TO 13.

NO

>> Replace front blower motor. Refer to 

VTL-12, "Removal and Installation"

.

13.

CHECK BLOWER MOTOR GROUND CIRCUIT

Check continuity between front blower motor harness connector

M62 (B) terminal 1 and variable blower control harness connector

M122 (A) terminal 2.

Is the inspection result normal?

YES

>> GO TO 14.

NO

>> Repair harness or connector.

14.

CHECK VARIABLE BLOWER CONTROL GROUND CIRCUIT

4 - Ground

: Continuity should not exist.

AWIIA0177ZZ

13 - 3

: Continuity should exist.

AWIIA0414ZZ

1 - 2

: Continuity should exist.

AWIIA0179ZZ

HAC-48

< DTC/CIRCUIT DIAGNOSIS >

[AUTOMATIC AIR CONDITIONER]

BLOWER MOTOR CONTROL SYSTEM

Check continuity between variable blower control harness connector

M122 terminal 1 and ground.

Is the inspection result normal?

YES

>> Replace variable blower control. Refer to 

VTL-22,

"Removal and Installation"

.

NO

>> Repair harness or connector.

Front Blower Motor Component Inspection

INFOID:0000000009882465

COMPONENT INSPECTION 

Check continuity between terminals 3, and 5 by supplying 12 volts

and ground to coil side terminals 1 and 2 of relay.

Front Blower Motor

Confirm smooth rotation of the blower motor.

• Ensure that there are no foreign particles inside the blower unit.

• Apply 12 volts to terminal 2 and ground to terminal 1 and verify that

the motor operates freely and quietly.

1 - Ground

: Continuity should exist.

AWIIA0180ZZ

WJIA1401E

WJIA1508E