NISSAN X-TRAIL 2003 Electronic Repair Manual

LUBRICANT
ATC-23
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AT CRHA065DI

ATC-24
AIR CONDITIONER CONTROL
AIR CONDITIONER CONTROL
PFP:27500
Overview Air Conditioner LAN Control SystemEJS000TI
The LAN system consists of auto amp., mode door motor, air mix door motor and intake door motor.
A configuration of these components is shown in the diagram below.
System ConstructionEJS000TJ
A small network is constructed between the auto amplifier, air mix door motor and mode door motor. The auto
amplifier and motors are connected by data transmission lines and motor power supply lines. The LAN net-
work is built through the ground circuits of the two motors.
Addresses, motor opening angle signals, motor stop signals and error checking messages are all transmitted
through the data transmission lines connecting the auto amplifier and two motors.
The following functions are contained in LCUs built into the air mix door motor and the mode door motor.
lAddress
lMotor opening angle signals
lData transmission
lMotor stop and drive decision
lOpening angle sensor (PBR function)
lComparison
lDecision (Auto amplifier indicated value and motor opening angle comparison)
OPERATION
The auto amplifier receives data from each of the sensors. The amplifier sends mode door, air mix door and
intake door opening angle data to the mode door motor LCU, air mix door motor LCU and intake door motor
LCU.
The mode door motor, air mix 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, DEFROST/VENT or FRESH/RECIRCULATION operation is selected. The new selection
data is returned to the auto amplifier.
RJIA0480E
RHA350H

AIR CONDITIONER CONTROL
ATC-25
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TRANSMISSION DATA AND TRANSMISSION ORDER
Amplifier data is transmitted consecutively to each of the door motors following the form shown in figure below.
Start: Initial compulsory signal sent to each of the door motors.
Address: Data sent from the auto amplifier is selected according to data-based decisions made by the air mix
door motor, mode door motor and intake door motor.
If the addresses are identical, the opening angle data and error check signals are received by the door motor
LCUs. The LCUs then make the appropriate error decision. If the opening angle data is normal, door control
begins.
If an error exists, the received data is rejected and corrected data received. Finally, door control is based upon
the corrected opening angle data.
Opening angle:
Data that shows the indicated door opening angle of each door motor.
Error check:
Procedure by which sent and received data is checked for errors. Error data is then compiled. The error check
prevents corrupted data from being used by the air mix door motor, mode door motor and intake door motor.
Error data can be related to the following problems.
lAbnormal electrical frequency
lPoor electrical connections
lSignal leakage from transmission lines
lSignal level fluctuation
Stop signal:
At the end of each transmission, a stop operation, in-operation, or internal problem message is delivered to
the auto amplifier. This completes one data transmission and control cycle.
AIR MIX DOOR CONTROL (AUTOMATIC TEMPERATURE CONTROL)
The air mix door is automatically controlled so that in-vehicle temperature is maintained at a predetermined
value by: The temperature setting, ambient temperature, in-vehicle temperature and amount of sunload.
RHA351H
RHA352H

ATC-26
AIR CONDITIONER CONTROL
FAN SPEED CONTROL
Blower speed is automatically controlled based on temperature setting, ambient temperature, in-vehicle tem-
perature, intake temperature, amount of sunload and air mix door position.
With FAN switch set to AUTO, the blower motor starts to gradually increase air flow volume.
When engine coolant temperature is low, the blower motor operation is delayed to prevent cool air from flow-
ing.
INTAKE DOOR CONTROL
The intake doors are automatically controlled by: The temperature setting, ambient temperature, in-vehicle
temperature, intake temperature, amount of sunload and ON-OFF operation of the compressor.
OUTLET DOOR CONTROL
The outlet door is automatically controlled by: The temperature setting, ambient temperature, in-vehicle tem-
perature, intake temperature and amount of sunload.
MAGNET CLUTCH CONTROL
The ECM controls compressor operation using input signals from the throttle position sensor and auto ampli-
fier.
SELF-DIAGNOSTIC SYSTEM
The self-diagnostic system is built into the auto amplifier (LCU) to quickly locate the cause of problems.
Overview of Control systemEJS000TK
The control system consists of input sensors, switches, the automatic amplifier (microcomputer) and outputs.
The relationship of these components is shown in the diagram below:
RJIA0481E

AIR CONDITIONER CONTROL
ATC-27
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Control OperationEJS000TL
DISPLAY SCREEN
Displays the operational status of the system.
AUTO SWITCH
The compressor, intake doors, air mix doors, outlet doors and blower speed are automatically controlled so
that the in-vehicle temperature will reach, and be maintained at the set temperature selected by the operator.
TEMPERATURE DIAL (POTENTIO TEMPERATURE CONTROL)
Increase or decrease the set temperature.
Ambient temperature will be displayed by pressing the temperature dial.
A/C SWITCH
The compressor is ON or OFF.
(Pressing the A/C switch when the AUTO switch is ON will turn off the A/C switch and compressor.)
DEFROSTER (DEF) SWITCH
Positions the air outlet doors to the defrost position. Also positions the intake doors to the outside air position.
MODE SWITCH
Control the air discharge outlets.
FAN S WIT CH
Manually controls the blower speed. Five speeds are available for manual control (as shown on the display
screen).
OFF SWITCH
The compressor and blower are OFF, the intake doors are set to the outside air position, and the air outlet
doors are set to the foot position.
FRESH (FRE) SWITCH
OFF position: Interior air is recirculated inside the vehicle.
ON position: Outside air is drawn into the passenger compartment.
(When RECICULATION switch is ON, the FRESH switch turns OFF automatically.)
RECIRCULATION (REC) SWITCH
OFF position: Outside air is drawn into the passenger compartment.
ON position: Interior air is drawn into the passenger compartment.
(When the FRESH switch is ON or the compressor is turned from ON to OFF, the RECIRCULATION switch
turns OFF automatically.)
RJIA0482E

ATC-28
AIR CONDITIONER CONTROL
Discharge Air Flow
EJ S00 0T M
RJIA0483E

AIR CONDITIONER CONTROL
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System DescriptionEJS000TN
SWITCHES AND THEIR CONTROL FUNCTION
RJIA0484E
RJIA0485E

ATC-30
TROUBLE DIAGNOSIS
TROUBLE DIAGNOSIS
PFP:00004
How to Perform Trouble Diagnoses for Quick and Accurate RepairEJS001GS
WORK FLOW
SYMPTOM TABLE
*1 Operational heckAT C -5 1
SHA900E
Symptom Reference Page
A/C system does not come on. Go to Trouble Diagnosis Procedure for A/C system.AT C - 5 3
Air outlet does not change.
Go to Trouble Diagnosis Procedure for Mode Door Motor. (LAN)AT C - 5 8
Mode door motor does not operate normally.
Discharge air temperature does not change.
Go to Trouble Diagnosis Procedure for Air Mix Door Motor. (LAN)AT C - 6 1
Air mix door motor does not operate nor-
mally.
Intake door does not change.
Go to Trouble Diagnosis Procedure for Intake Door Motor.(LAN)AT C - 6 4
Intake door motor does not operate normally.
Blower motor operation is malfunctioning.
Go to Trouble Diagnosis Procedure for Blower Motor.AT C - 6 7
Blower motor operation is malfunctioning
under out of starting fan speed control.
Magnet clutch does not engage. Go to Trouble Diagnosis Procedure for Magnet Clutch.AT C - 7 3
Insufficient cooling. Go to Trouble Diagnosis Procedure for Insufficient Cooling.AT C - 8 1
Insufficient heating. Go to Trouble Diagnosis Procedure for Insufficient Heating.AT C - 8 9
Noise. Go to Trouble Diagnosis Procedure for Noise.AT C - 9 1
Self-diagnosis can not be performed. Go to Trouble Diagnosis Procedure for Self-diagnosis.AT C - 9 2
Memory function does not operate. Go to Trouble Diagnosis Procedure for Memory Function.AT C - 9 2

TROUBLE DIAGNOSIS
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Component Parts and Harness Connector LocationEJS001GT
ENGINE COMPARTMENT
RJIA0486E

ATC-32
TROUBLE DIAGNOSIS
PASSENGER COMPARTMENT
RJIA0487E