NISSAN X-TRAIL 2001 Service Repair Manual

TROUBLE DIAGNOSIS
ATC-65
C
D
E
F
G
H
I
K
L
MA
B
AT C
INSPECTION FLOW
*1ATC-47, "PROCEDURE", see No.1 *2ATC-100, "Ambient Sensor Circuit".*3ATC-102, "In-vehicle Sensor Circuit".
*4ATC-105, "
Sunload Sensor Circuit".*5ATC-64, "Air Mix Door Motor Circuit".*6ATC-47, "PROCEDURE", see No.
14.
*7ATC-59, "
LAN System Circuit".*8ATC-54, "Operational Check".*9ATC-54, "Operational Check".
*10ATC-33, "
SYMPTOM TABLE".*11ATC-108, "Intake Sensor Circuit".*12ATC-47, "PROCEDURE", see No. 5
to 7.
RJIA0515E

ATC-66
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 air mix door motor, mode door motor and intake door motor)
●In-vehicle sensor
●Ambient sensor
●Sunload sensor
●Intake sensor
System Operation
The auto amplifier receives data from each of the sensors. The amplifier sends air mix door, mode door and
intake door motor 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 amplifier and each of the motor posi-
tion sensors are compared by the LCUs in each motor with the existing decision and opening angles. Subse-
quently, HOT/COLD or DEFROST/VENT or FRESH/RECIRCULATION operation is selected. The new
selection data is returned to the auto amplifier.
COMPONENT DESCRIPTION
Air Mix Door Motor
The air mix door motor is attached to the heater & cooling unit. It
rotates so that the air mix door is opened or closed to a position set
by the auto amplifier. The air mix door position is then fed back to the
auto amplifier by PBR built-in air mix door motor.
RHA424GB
RJIA0516E

TROUBLE DIAGNOSIS
ATC-67
C
D
E
F
G
H
I
K
L
MA
B
AT C
Air Mix Door Control Specification
DIAGNOSTIC PROCEDURE
SYMPTOM: Discharge air temperature does not change.
Perform diagnostic procedure for ATC-59, "
LAN System Circuit" .
RJIA0517E
RHA457H

ATC-68
TROUBLE DIAGNOSIS
Intake Door Motor Circuit
EJS001H3
SYMPTOM:
●Intake door does not change.
●Intake door motor does not operate normally.
INSPECTION FLOW
*1AT C - 9 8 , "Self-diagnosis", see No.1 *2ATC-100, "Ambient Sensor Circuit".*3ATC-102, "In-vehicle Sensor Cir-
cuit".
*4AT C - 1 0 5 , "
Sunload Sensor Circuit".*5ATC-64, "Air Mix Door Motor Circuit".*6ATC-47, "PROCEDURE", see No.
14.
*7AT C - 5 9 , "
LAN System Circuit".*8ATC-119, "INTAKE DOOR MOTOR".*9ATC-54, "Operational Check".
*10AT C - 4 7 , "
PROCEDURE", see No. 5
to 7.*11ATC-54, "Operational Check".*12ATC-33, "SYMPTOM TABLE".
*13ATC-108, "
Intake Sensor Circuit".
RJIA0518E

TROUBLE DIAGNOSIS
ATC-69
C
D
E
F
G
H
I
K
L
MA
B
AT C
SYSTEM DESCRIPTION
Component Parts
Intake door control system components are:
●Auto amp.
●Intake door motor (LCU)
●A/C LAN system (PBR built-in air mix door motor, mode door motor and intake door motor)
●In-vehicle sensor
●Ambient sensor
●Sunload sensor
●Intake sensor
System Operation
The auto amplifier receives data from each of the sensors. The amplifier sends air mix door, mode door and
intake door motor 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 amplifier and each of the motor posi-
tion sensors are compared by the LCUs in each motor with the existing decision and opening angles. Subse-
quently, HOT/COLD or DEFROST/VENT or FRESH/RECIRCULATION operation is selected. The new
selection data is returned to the auto amplifier.
COMPONENT DESCRIPTION
Intake Door Motor
The intake door motor is attached to the intake unit. It rotates so that
air is drawn from inlets set by the auto amplifier. Motor rotation is
conveyed to a lever which activates the intake door.
SHA431F
RJIA0519E

ATC-70
TROUBLE DIAGNOSIS
DIAGNOSTIC PROCEDURE
SYMPTOM: Intake door motor does not operate normally.
Perform diagnostic procedure for ATC-59, "
LAN System Circuit" .
Blower Motor CircuitEJS002FR
SYMPTOM:
●Blower motor operation is malfunctioning.
●Blower motor operation is malfunctioning under out of starting fan speed control.
RJIA0520E

TROUBLE DIAGNOSIS
ATC-71
C
D
E
F
G
H
I
K
L
MA
B
AT C
INSPECTION FLOW
*1ATC-47, "PROCEDURE".*2ATC-100, "Ambient Sensor Circuit".*3ATC-102, "In-vehicle Sensor Circuit".
*4ATC-105, "
Sunload Sensor Circuit".*5ATC-64, "Air Mix Door Motor Circuit".*6ATC-47, "PROCEDURE",see No. 13.
*7ATC-70, "
Blower Motor Circuit".*8ATC-47, "PROCEDURE" see 5 to 7. *9ATC-54, "Operational Check".
RJIA0521E

ATC-72
TROUBLE DIAGNOSIS
SYSTEM DESCRIPTION
Component Parts
Fan speed control system components are:
●Auto amp.
●A/C LAN system (PBR built-in air mix door motor, mode door motor and intake door motor)
●Fan control amp.
●In-vehicle sensor
●Ambient sensor
●Sunload sensor
●Intake sensor
System Operation
Automatic Mode
In the automatic mode, the blower motor speed is calculated by the automatic amplifier based on input from
the PBR, in-vehicle sensor, sunload sensor, intake sensor and ambient sensor.
The blower motor applied voltage ranges from approximately 4 volts (lowest speed) to 12 volts (highest
speed).
The control blower speed (in the range of 4 to 12V), the automatic amplifier supplies a gate voltage to the fan
control amplifier. Based on this voltage, the fan control amplifier controls the voltage supplied to the blower
motor.
*10AT C - 3 3 , "SYMPTOM TABLE".*11AT C - 5 4 , "Operational Check".*12ATC-108, "Intake Sensor Circuit".
*13 QR25 engine; (WITH EURO-OBD)
EC-153, "
ENGINE COOLANT TEM-
PERATURE SENSOR" .
QR25 engine; (WITHOUT EURO-
OBD)EC-527, "
ENGINE COOLANT
TEMPERATURE SENSOR" .
QR20 engine ; (WITH EURO-OBD),
EC-885, "
ENGINE COOLANT TEM-
PERATURE SENSOR" .
QR20 engine; (WITHOUT EURO-
OBD) EC-1213, "
ENGINE COOL-
ANT TEMPERATURE SENSOR" .
YD engine; EC-1459, "
ENGINE
COOLANT TEMPERATURE SEN-
SOR" .
SHA006FD

TROUBLE DIAGNOSIS
ATC-73
C
D
E
F
G
H
I
K
L
MA
B
AT C
Starting Fan Speed Control
Start Up From COLD SOAK Condition (Automatic mode)
In a cold start up condition where the engine coolant temperature is below 56°C, the blower will not operate for
a short period of time (up to 150 seconds). The exact start delay time varies depending on the ambient and
engine coolant temperature.
In the most extreme case (very low ambient) the blower starting delay will be 150 seconds as described
above. After this delay, the blower will operate at low speed until the engine coolant temperature rises above
56°C, at which time the blower speed will increase to the objective speed.
Start Up From Normal or HOT SOAK Condition (Automatic mode)
The blower will begin operation momentarily after the A/C button is pushed. The blower speed will gradually
rise to the objective speed over a time period of 3 seconds or less (actual time depends on the objective
blower speed).

ATC-74
TROUBLE DIAGNOSIS
Blower Speed Compensation
Sunload
When the in-vehicle temperature and the set temperature are very close, the blower will be operating at low
speed. The low speed will vary depending on the sunload. During conditions of low or no sunload, the blower
low speed is usual low speed (approx. 4V). During high sunload conditions, the auto amp causes the blower
fan speed to increase.(Approx. 7V)
Fan Speed Control Specification
COMPONENT DESCRIPTION
Fan Control Amplifier
The fan control amplifier is located on the intake unit. The fan control
amp. receives a gate voltage from the auto amp. to steplessly main-
tain the blower fan motor voltage in the 4 to 12 volt range.
DIAGNOSTIC PROCEDURE
SYMPTOM: Blower motor operation is malfunctioning under Starting
Fan Speed Control.
RJIA0522E
RJIA0523E
RHA467GA