Nissan Frontier D40. Manual - part 747

AIR MIX DOOR MOTOR

HAC-91

< COMPONENT DIAGNOSIS >

[MANUAL A/C (TYPE 2)]

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AIR MIX DOOR MOTOR

System Description

INFOID:0000000005275928

SYSTEM DESCRIPTION

Component Parts

Air mix door control system components are:

• Front air control
• Air mix door motor 
• PBR (built into air mix door motor)
• Intake sensor

System Operation

The front air control receives data from the temperature selected by the driver. The front air control then
applies a voltage to one circuit of the air mix door motor, while ground is applied to the other circuit, causing
the air mix 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 air mix door positions by measur-
ing the voltage signal on the PBR circuits of each door.

Air Mix Door Control Specification

COMPONENT DESCRIPTION

Air Mix Door Motor

WJIA1316E

WJIA0435E

HAC-92

< COMPONENT DIAGNOSIS >

[MANUAL A/C (TYPE 2)]

AIR MIX DOOR MOTOR

The air mix door motor is attached to the heater and cooling unit
assembly. This motor rotates so that the air mix door is opened or
closed to a position set by the front air control. Motor rotation is then
conveyed through a shaft and the air mix door position is then fed
back to the front air control by the PBR built into the air mix door
motor.

Air Mix Door Motor Component Function Check

INFOID:0000000005275929

INSPECTION FLOW

1.

CONFIRM SYMPTOM BY PERFORMING OPERATIONAL CHECK - TEMPERATURE INCREASE

1.

Blower must be on (1, 2, 3, 4).

2.

Turn the temperature control dial clockwise to maximum heat.

3.

Check for hot air at discharge air outlets.

>> GO TO 2.

2.

CONFIRM SYMPTOM BY PERFORMING OPERATIONAL CHECK - TEMPERATURE DECREASE

1.

Turn the temperature control dial counterclockwise to maximum cold.

2.

Check for cold air at discharge air outlets.

Is the inspection result normal?

YES

>> Inspection End.

NO

>> Go to diagnosis procedure. Refer to 

HAC-92, "Air Mix Door Motor Diagnosis Procedure"

.

Air Mix Door Motor Diagnosis Procedure

INFOID:0000000005275930

Regarding Wiring Diagram information, refer to 

HAC-117, "Wiring Diagram - Air Conditioner Control - Without

VBC"

.

DIAGNOSTIC PROCEDURE FOR AIR MIX DOOR MOTOR

1.

CHECK POWER SUPPLY CIRCUITS FOR AIR MIX DOOR MOTOR

1.

Turn ignition switch OFF.

2.

Disconnect front air control connector and air mix door motor
connector.

3.

Check continuity between front air control harness connector
M49 terminal 2 and 3 and air mix door motor harness connector
M147 terminal 6 and 5.

Is inspection result normal?

YES

>> GO TO 2.

NO

>> Repair or replace harness as necessary.

2.

CHECK PBR REFERENCE SIGNAL VOLTAGE

WJIA1636E

2 - 6

: Continuity should exist.

3 - 5

: Continuity should exist.

WJIA1638E

AIR MIX DOOR MOTOR

HAC-93

< COMPONENT DIAGNOSIS >

[MANUAL A/C (TYPE 2)]

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1.

Reconnect the front air control connector.

2.

Turn ignition switch ON.

3.

Check voltage between air mix door motor harness connector
M147 terminal 1 and ground.

Is inspection result normal?

YES

>> GO TO 4.

NO

>> GO TO 3.

3.

CHECK PBR REFERENCE VOLTAGE CIRCUIT BETWEEN AIR MIX DOOR MOTOR AND FRONT AIR

CONTROL

1.

Turn ignition switch OFF.

2.

Disconnect the front air control connector.

3.

Check continuity between air mix door motor harness connector
M147 (B) terminal 1 and front air control harness connector M49
(A) terminal 23.

Is inspection result normal?

YES

>> Replace front air control. Refer to 

VTL-7, "Removal and Installation"

.

NO

>> Repair or replace harness as necessary.

4.

CHECK PBR GROUND REFERENCE CIRCUIT 

1.

Turn ignition switch OFF.

2.

Disconnect the front air control connector.

3.

Check continuity between air mix door motor harness connector
M147 terminal 3 and front air control harness connector M49 ter-
minal 26.

Is inspection result normal?

YES

>> GO TO 5.

NO

>> Repair or replace harness as necessary.

5.

CHECK PBR FEEDBACK SIGNAL

1.

Reconnect the front air control connector and air mix door motor
connector.

2.

Turn ignition switch ON.

3.

Check voltage between front air control harness connector M49
terminal 22 and ground.

4.

Rotate temperature control dial through complete range.

Is inspection result normal?

YES

>> Replace front air control. Refer to 

VTL-7, "Removal and

Installation"

.

NO

>> GO TO 6.

6.

CHECK PBR FEEDBACK CIRCUIT

 1 - Ground

: Approx. 5V

WJIA1637E

A

B

Connector

Terminal Connector

Terminal 

Continuity

Front air control: 

M49

23 

Air mix door mo-

tor: M147

1

Yes

WJIA1656E

3 - 26

: Continuity should exist.

WJIA1640E

22 - Ground

: Approx. 0V - 5V

WJIA1096E

HAC-94

< COMPONENT DIAGNOSIS >

[MANUAL A/C (TYPE 2)]

AIR MIX DOOR MOTOR

1.

Turn ignition switch OFF.

2.

Disconnect the air mix door motor connector and front air control
connector.

3.

Check continuity between air mix door motor harness connector
M147 terminal 2 and front air control harness connector M49 ter-
minal 22.

Is inspection result normal?

YES

>> Replace air mix door motor. Refer to 

VTL-19, "Removal

and Installation"

.

NO

>> Repair or replace harness as necessary.

2 - 22

: Continuity should exist.

WJIA1641E