Nissan Titan. Manual - part 383

INTAKE DOOR MOTOR

HAC-37

< DTC/CIRCUIT DIAGNOSIS >

[AUTOMATIC AIR CONDITIONER]

C

D

E

F

G

H

J

K

L

M

A

B

HAC

N

O

P

4. Check continuity between front air control harness connector

M49 terminals 21, 22 and ground.

Is the inspection result normal?

YES

>> GO TO 3.

NO

>> Repair or replace harness as necessary.

2.

CHECK FRONT AIR CONTROL FOR INTAKE AIR DOOR MOTOR POWER AND GROUND 

1. Reconnect front air control harness connector.

2. Turn ignition switch ON.

3. Check voltage between front air control harness connector M49

terminal 21 and terminal 22 while placing the HVAC system into

self-diagnostic mode.

Is the inspection result normal?

YES

>> Inspect intake air door for binding or mechanical failure. If intake air door moves freely, replace the

intake air door motor. Refer to 

VTL-18, "Removal and Installation"

.

NO

>> Replace front air control. Refer to 

VTL-8, "Removal and Installation"

.

Connector

Terminal

—

Continuity

M49

21

Ground

No

22

AWIIA0398ZZ

Connector

Terminals

Condition Voltage 

(Approx.)

(+) (-)

M49

21

22

Self-diagnostic mode (opening)

Battery voltage

22

21

Self-diagnostic mode (closing)

Battery voltage

AWIIA0397ZZ

HAC-38

< DTC/CIRCUIT DIAGNOSIS >

[AUTOMATIC AIR CONDITIONER]

DEFROSTER DOOR MOTOR CIRCUIT

DEFROSTER DOOR MOTOR CIRCUIT

System Description

INFOID:0000000009882459

SYSTEM DESCRIPTION

Component Parts

Defroster door control system components are:

• Front air control

• Defroster door motor

• PBR (Built into defroster door motor)

• In-vehicle sensor

• Ambient sensor

• Optical sensor

• Intake sensor

System Operation

The front air control determines defroster door position based on the position of the defroster switch. When the

defroster switch is depressed, the defroster door motor rotates directing air to the defroster ducts. When any

mode other than defroster is selected, the defroster motor rotates in the opposite direction closing off air flow

to the defroster ducts.

In the AUTO mode, the front air control determines defroster door position based on the ambient temperature,

the intake air temperature and the in-vehicle temperature.

COMPONENT DESCRIPTION

Defroster door motor 

The defroster door motor is attached to the front heater & cooling

unit assembly. The front air control sends a voltage to rotate to the

defroster door directing the air flow either to the defroster ducts, or to

the foot ducts, depending on which way the voltage and ground are

applied to the motor leads. Motor rotation is conveyed to a lever

which activates the defroster door.

Defroster Door Motor Component Function Check

INFOID:0000000009882460

INSPECTION FLOW

WJIA1354E

WJIA0592E

DEFROSTER DOOR MOTOR CIRCUIT

HAC-39

< DTC/CIRCUIT DIAGNOSIS >

[AUTOMATIC AIR CONDITIONER]

C

D

E

F

G

H

J

K

L

M

A

B

HAC

N

O

P

1.

CONFIRM SYMPTOM BY PERFORMING OPERATIONAL CHECK - DEFROSTER DOOR

1. Select vent (

) mode.

2. Press the defrost switch (

). Defroster indicator should illuminate. 

3. Listen for defroster door position change (blower sound should change slightly).
Is the inspection result normal?

YES

>> Inspection End.

NO

>> Go to diagnosis procedure. Refer to 

HAC-39, "Defroster Door Motor Diagnosis Procedure"

.

Defroster Door Motor Diagnosis Procedure

INFOID:0000000009882461

Regarding Wiring Diagram information, refer to 

HAC-71, "Wiring Diagram - Automatic Air Conditioner"

.

SYMPTOM:

• Defroster door does not change.

• Defroster door motor does not operate normally.

1.

CHECK DEFROSTER DOOR MOTOR POSITION BALANCED RESISTOR (PBR) FEEDBACK VOLTAGE

1. Turn ignition switch ON.

2. Using CONSULT, check "DEF FDBCK" in "DATA MONITOR" mode in "HVAC". Refer to 

HAC-17, "CON-

SULT Function (HVAC)"

.

3. Observe "DEF FDBCK" voltage while cycling front air control mode switch through all modes and pressing

DEF switch.

Is the inspection result normal?

YES

>> • Defroster door motor is OK.

• Inspect defroster door for mechanical failure. Refer to 

VTL-17, "Removal and Installation"

.

NO

>> GO TO 2.

2.

CHECK DEFROSTER DOOR MOTOR CIRCUITS FOR OPEN AND SHORT TO GROUND 

1. Turn ignition switch OFF.

2. Disconnect the front air control harness connector M49 (A) and

the defroster door motor harness connector M144 (B).

3. Check continuity between front air control harness connector

M49 (A) terminals 23, 24 and the defroster door motor harness

connector M144 (B) terminals 1, 6.

Monitor Item

Condition

Results

DEF FDBCK

Cycle mode switch through all modes, D/F 

(

), VENT (

), B/L (

), FOOT(

), and 

press DEF (

)

Voltage varies between 0.2 and 4.8 volts.

A

B

Continuity

Connector

Terminal

Connector

Terminal

M49

23

M144

1

Yes

24

6

AWIIA0406ZZ

HAC-40

< DTC/CIRCUIT DIAGNOSIS >

[AUTOMATIC AIR CONDITIONER]

DEFROSTER DOOR MOTOR CIRCUIT

4. Check continuity between front air control harness connector

M49 terminals 23, 24 and ground.

Is the inspection result normal?

YES

>> GO TO 3.

NO

>> Repair or replace harness as necessary.

3.

CHECK FRONT AIR CONTROL FOR DEFROSTER DOOR MOTOR POWER AND GROUND 

1. Reconnect front air control harness connector.

2. Turn ignition switch ON.
3. Press the mode switch to the VENT (

) mode. 

4. Check voltage between front air control harness connector M49

terminal 23 and terminal 24 while pressing the defroster switch
(

). 

Is the inspection result normal?

YES

>> GO TO 4.

NO

>> Replace front air control. Refer to 

VTL-8, "Removal and Installation"

.

4.

CHECK DEFROSTER DOOR MOTOR PBR CIRCUITS FOR OPEN AND SHORT TO GROUND 

1. Turn ignition switch OFF.

2. Disconnect the front air control harness connectors M49 (C) and

M50 (A).

3. Check continuity between front air control harness connector

M49 (C) terminal 3, and M50 (A) terminal 28 and the defroster

door motor harness connector M144 (B) terminals 2, 3.

4. Check continuity between front air control harness connector M49 (C) terminal 3, M50 (A) terminal 28 and

ground.

Is the inspection result normal?

YES

>> GO TO 5.

NO

>> Repair or replace harness as necessary.

5.

CHECK PBR FEEDBACK SIGNAL CIRCUIT FOR OPEN AND SHORT TO GROUND 

Connector

Terminal

—

Continuity

M49

23

Ground

No

24

AWIIA0403ZZ

Connector

Terminals

Condition Voltage 

(Approx.)

(+) (-)

M49

23

24

Following defroster switch (

) on

Battery voltage

24

23

Following defroster switch (

) off

Battery voltage

AWIIA0404ZZ

A and C

B

Continuity

Connector

Terminal

Connector

Terminal

M49 (C)

3

M144

2

Yes

M50 (A)

28

3

Connector

Terminal

—

Continuity

M49 (C)

3

Ground

No

M50 (A)

28

AWIIA0393ZZ