Nissan Titan. Manual - part 423

MODE DOOR MOTOR

HAC-197

< DTC/CIRCUIT DIAGNOSIS >

[MANUAL A/C (TYPE 2)]

C

D

E

F

G

H

J

K

L

M

A

B

HAC

N

O

P

MODE DOOR MOTOR

System Description

INFOID:0000000009882575

SYSTEM DESCRIPTION

Component Parts

Mode door control system components are:

• Front air control

• Mode door motor

• PBR (built into mode door motor)

• Intake sensor

System Operation

The mode door position (vent, B/L, foot, D/F, and defrost) is set by the front air control by means of the mode

door motor. When a mode door position is selected on the front air control, voltage is applied to one circuit of

the mode door motor while ground is applied to the other circuit, causing the mode door motor to rotate. The

direction of rotation is determined by which circuit has voltage applied to it, and which one has ground applied

to it. The front air control monitors the mode door position by measuring the voltage signal on the PBR circuit.

COMPONENT DESCRIPTION

Mode Door Motor 

The mode door motor is attached to the heater & cooling unit assem-

bly. It rotates so that air is discharged from the outlet as indicated by

the front air control. Motor rotation is conveyed to a link which acti-

vates the mode door.

Mode Door Motor Component Function Check

INFOID:0000000009882576

INSPECTION FLOW

1.

CONFIRM SYMPTOM BY PERFORMING OPERATIONAL CHECK - DISCHARGE AIR

1. Rotate the mode control dial and check each position and press the 

 (DEF) mode.

2. Confirm that discharge air comes out according to the air distribution table. Refer to 

HAC-191, "Discharge

Air Flow"

.

NOTE:

Confirm that the compressor clutch is engaged (visual inspection) and intake door position is at FRESH

 when DEF (

) or D/F (

) is selected.

Is the inspection result normal?

YES

>> Inspection End.

NO

>> Go to diagnosis procedure. Refer to 

HAC-197, "Mode Door Motor Diagnosis Procedure"

.

Mode Door Motor Diagnosis Procedure

INFOID:0000000009882577

Regarding Wiring Diagram information, refer to 

HAC-232, "Wiring Diagram - Manual With 3 Control Dial Sys-

tem"

.

SYMPTOM:

• Air outlet does not change.

WJIA0587E

HAC-198

< DTC/CIRCUIT DIAGNOSIS >

[MANUAL A/C (TYPE 2)]

MODE DOOR MOTOR

• Mode door motor does not operate normally.

1.

CHECK MODE DOOR MOTOR CIRCUITS FOR OPEN AND SHORT TO GROUND 

1. Turn ignition switch OFF.

2. Disconnect the front air control harness connector M176 (A) and

the mode door motor harness connector M142 (B).

3. Check continuity between front air control harness connector

M176 (A) terminals 5, 6 and the mode door motor harness con-

nector M142 (B) terminals 5, 6.

4. Check continuity between front air control harness connector

M176 terminals 5, 6 and ground.

Is the inspection result normal?

YES

>> GO TO 3.

NO

>> Repair or replace harness as necessary.

2.

CHECK FRONT AIR CONTROL FOR MODE DOOR MOTOR POWER AND GROUND 

1. Reconnect front air control harness connector.

2. Turn ignition switch ON.
3. Rotate the mode switch to the D/F (

) mode. 

4. Check voltage between front air control harness connector

M176 terminal 5 and terminal 6 while rotating the mode control
dial to the VENT (

), and then the B/L (

) mode. 

Is the inspection result normal?

YES

>> GO TO 4.

NO

>> Replace front air control. Refer to 

VTL-8, "Removal and Installation"

.

3.

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

A

B

Continuity

Connector

Terminal

Connector

Terminal

M176

5

M142

5

Yes

6

6

Connector

Terminal

—

Continuity

M176

5

Ground

No

6

AWIIA0493ZZ

AWIIA0490ZZ

Connector

Terminals

Condition Voltage 

(Approx.)

(+) (-)

M176

5

6

Rotating the mode control dial from 

D/F (

) mode to VENT (

) mode

Battery voltage

6

5

Rotating the mode control dial from 

VENT (

) mode to B/L (

) mode

Battery voltage

AWIIA0489ZZ

MODE DOOR MOTOR

HAC-199

< DTC/CIRCUIT DIAGNOSIS >

[MANUAL A/C (TYPE 2)]

C

D

E

F

G

H

J

K

L

M

A

B

HAC

N

O

P

1. Turn ignition switch OFF.

2. Disconnect the front air control harness connector M176 (A).

3. Check continuity between front air control harness connector

M176 (A) terminals 2, 15 and the mode door motor harness con-

nector M142 (B) terminals 1, 3.

4. Check continuity between front air control harness connector

M176 terminals 2, 15 and ground.

Is the inspection result normal?

YES

>> GO TO 5.

NO

>> Repair or replace harness as necessary.

4.

CHECK PBR FEEDBACK SIGNAL CIRCUIT FOR OPEN AND SHORT TO GROUND 

1. Check continuity between front air control harness connector

M176 (A) terminal 16 and mode door motor harness connector

M142 (B) terminal 2.

2. Check continuity between front air control harness connector

M176 terminal 16 and ground.

Is the inspection result normal?

YES

>> GO TO 6.

NO

>> Repair or replace harness as necessary.

5.

CHECK FRONT AIR CONTROL FOR 5 VOLT REFERENCE (VREF), VREF RETURN, AND FEEDBACK

SIGNAL 

A

B

Continuity

Connector

Terminal

Connector

Terminal

M176

2

M142

1

Yes

15

3

Connector

Terminal

—

Continuity

M176

2

Ground

No

15

AWIIA0498ZZ

A

B

Continuity

Connector

Terminal

Connector

Terminal

M176

16

M142

2

Yes

AWIIA0503ZZ

Connector

Terminal

—

Continuity

M176

16

Ground

No

AWIIA0499ZZ

HAC-200

< DTC/CIRCUIT DIAGNOSIS >

[MANUAL A/C (TYPE 2)]

MODE DOOR MOTOR

1. Reconnect front air control harness connectors.

2. Turn ignition switch ON.

3. Check voltage between front air control harness connector

M176 terminal 2 and terminal 15.

4. Check voltage between front air control harness connector

M176 terminal 16 and ground.

Is the inspection result normal?

YES

>> GO TO 7.

NO

>> Replace front air control. Refer to 

VTL-8, "Removal and

Installation"

.

6.

CHECK FRONT AIR CONTROL FOR FEEDBACK SIGNAL 

1. Reconnect the mode door motor harness connector M142.

2. Check voltage between front air control harness connector

M176 terminal 16 and ground.

Is the inspection result normal?

YES

>> Inspect mode door for binding or mechanical failure. If

mode door moves freely, replace front air control. Refer

to 

VTL-8, "Removal and Installation"

.

NO

>> Replace the mode door motor. Refer to 

VTL-19,

"Removal and Installation"

.

Connector

Terminals

Connector

Terminals

Voltage (Approx.)

(+)

(-) 

M176

2

M176

15

5 Volts

AWIIA0495ZZ

Connector

Terminal

—

Voltage (Approx.)

M176

16

Ground

0 Volts

AWIIA0499ZZ

Connector

Terminal

—

Voltage (Approx.)

M176

16

Ground

0.2 to 4.8 Volts

AWIIA0499ZZ