Infiniti Q45. Manual — part 119

TROUBLE DIAGNOSIS

ATC-71

C

D

E

F

G

H

I

K

L

M

A

B

ATC

SYSTEM DESCRIPTION
Component Parts

Mode door control system components are:

●

Auto amp.

●

Mode door motor (LCU)

●

A/C LAN system (PBR built-in mode door motor, air mix door motor and intake door motor)

●

In-vehicle sensor

●

Ambient sensor

●

Sunload sensor

●

Intake sensor

System Operation

The auto amp. receives data from each of the sensors. The auto amp. sends air mix door, mode door and
intake door opening angle data to the air mix door motor LCU, mode door motor LCU and intake door motor
LCU.
The air mix door motor, mode door motor and intake door motor read their respective signals according to the
address signal. Opening angle indication signals received from the auto amp. and each of the motor position
sensors are compared by the LCUs in each door motor with the existing decision and opening angles. Subse-
quently, HOT/COLD, DEF/VENT and FRESH/RECIRCULATION operation is selected. The new selection data
are returned to the auto amp.

Mode Door Control Specification

RJIA1287E

RHA384HA

ATC-72

TROUBLE DIAGNOSIS

COMPONENT DESCRIPTION
Mode Door Motor

The mode door motor is attached to the heater & cooling unit. It
rotates so that air is discharged from the outlet set by the auto amp.
Motor rotation is conveyed to a link which activates the mode door.

DIAGNOSIS PROCEDURE FOR MODE DOOR MOTOR

SYMPTOM: Mode door motor does not operate normally.
Perform diagnosis procedure. Refer to

ATC-66, "DIAGNOSIS PROCEDURE FOR LAN CIRCUIT"

.

RJIA0283E

RJIA0284E

TROUBLE DIAGNOSIS

ATC-73

C

D

E

F

G

H

I

K

L

M

A

B

ATC

Air Mix Door Motor Circuit

NJS0008G

SYMPTOM:

●

Discharge air temperature does not change.

●

Air mix door motor does not operate normally.

INSPECTION FLOW

*1

ATC-54, "FUNCTION CONFIRMA-
TION PROCEDURE"

, see No. 1.

*2

ATC-110, "Ambient Sensor Circuit"

*3

ATC-112, "In-Vehicle Sensor Circuit"

*4

ATC-115, "Sunload Sensor Circuit"

*5

ATC-75, "Air Mix Door Motor PBR
Circuit"

*6

ATC-54, "FUNCTION CONFIRMA-
TION PROCEDURE"

, see No. 14.

*7

ATC-66, "LAN System Circuit"

*8

ATC-141, "AIR MIX DOOR MOTOR"

*9

ATC-62, "Operational Check"

*10

ATC-35, "SYMPTOM TABLE"

*11

ATC-118, "Intake Sensor Circuit"

*12

ATC-54, "FUNCTION CONFIRMA-
TION PROCEDURE"

, see No. 5 to 7.

RJIA3199E

ATC-74

TROUBLE DIAGNOSIS

SYSTEM DESCRIPTION
Component Parts

Air mix door control system components are:

●

Auto amp.

●

Air mix door motor (LCU)

●

A/C LAN system (PBR built-in mode door motor, air mix door motor and intake door motor)

●

In-vehicle sensor

●

Ambient sensor

●

Sunload sensor

●

Intake sensor

System Operation

The auto amp. receives data from each of the sensors. The auto amp. sends air mix door, mode door and
intake door opening angle data to the air mix door motor LCU, mode door motor LCU and intake door motor
LCU.
The air mix door motor, mode door motor and intake door motor read their respective signals according to the
address signal. Opening angle indication signals received from the auto amp. and each of the motor position
sensors are compared by the LCUs in each door motor with the existing decision and opening angles. Subse-
quently, HOT/COLD, DEF/VENT and FRESH/RECIRCULATION operation is selected. The new selection data
are returned to the auto amp.

Air Mix Door Control Specification

RJIA1289E

RHA457H