2003 NISSAN ALMERA N16 Engine Control

REFRIGERATION SYSTEM
ATC-15
C
D
E
F
G
H
I
K
L
MA
B
AT C
REFRIGERATION SYSTEMPFP:KA990
Refrigerant CycleEJS001Z0
REFRIGERANT FLOW
The refrigerant flows in the standard pattern, that is, through the compressor, the condenser with liquid tank,
through the evaporator, and back to the compressor. The refrigerant evaporation through the evaporator coil is
controlled by an externally equalized expansion valve, located inside the evaporator case.
FREEZE PROTECTION
Under usual operating conditions, when the A/C is switched on, the compressor runs continuously, and the
evaporator pressure, and therefore, temperature is controlled by the CSV613 displacement compressor to
prevent freeze up.
Refrigerant System ProtectionEJS001Z1
REFRIGERANT PRESSURE SENSOR (WITH GASOLINE ENGINE)
The refrigerant system is protected against excessively high or low pressures by the refrigerant pressure sen-
sor, located on the liquid tank. If the system pressure rises above, or falls below the specifications, the refriger-
ant pressure sensor detects the pressure inside the refrigerant line and sends the voltage signal to the ECM.
ECM makes the A/C relay go OFF and stops the compressor when pressure on the high pressure side
detected by refrigerant pressure sensor is over about 2,746 kPa (27.5 bar, 28 kg/cm
2 , 398 psi), or below
about 134 kPa (1.37 bar, 1.4 kg/cm
2 , 20 psi).
DUAL-PRESSURE SWITCH (WITH DIESEL ENGINE)
The refrigerant system is protected against excessively high or low pressures by the dual-pressure switch,
located on the liquid tank. If the system pressure rises above or falls below the specifications, the dual-pres-
sure switch opens to interrupt the compressor operation.
PRESSURE RELIEF VALVE
The refrigerant system is also protected by a pressure relief valve, located in the rear head of the compressor.
When the pressure of refrigerant in the system increases to an unusual level [more than 3,727 kPa (37.3 bar,
38 kg/cm
2 , 540 psi)], the release port on the pressure relief valve automatically opens and releases refriger-
ant into the atmosphere.
RHA682H

ATC-16
REFRIGERATION SYSTEM
CSV613 Variable Displacement Compressor
EJS001Z2
GENERAL INFORMATION
1. The CSV613 compressor differs from previous units. The vent temperatures of the CSV613 compressor
do not drop too far below 5°C (41°F) when:
Evaporator intake air temperature is less than 20°C (68°F).
Engine is running at speeds less than 1,500 rpm.
This is because the CSV613 compressor provides a means of “capacity” control.
2. The CSV613 compressor provides refrigerant control under varying conditions. During cold winters, it may
not produce high refrigerant pressure discharge (compared to previous units) when used with air condi-
tioning systems.
3. A “clanking” sound may occasionally be heard during refrigerant charge. The sound indicates that the tilt
angle of the swash plate has changed and is not a problem.
4. For air conditioning systems with the CSV613 compressor, the clutch remains engaged unless: the sys-
tem main switch, fan switch or ignition switch is turned OFF. When ambient (outside) temperatures are
low or when the amount of refrigerant is insufficient, the clutch is disengaged to protect the compressor.
5. A constant range of suction pressure is maintained when engine speed is greater than a certain value. It
normally ranges from 147 to 177 kPa (1.47 to 1.77 bar, 1.5 to 1.8 kg/cm
2 , 21 to 26 psi) under varying con-
ditions.
In previous compressors, however, suction pressure was reduced with increases in engine speed.
DESCRIPTION
General
The variable compressor is basically a swash plate type that changes piston stroke in response to the required
cooling capacity.

ATC-20
LUBRICANT
LUBRICANT
PFP:KLG00
Maintenance of Lubricant Quantity in CompressorEJS001Z4
The lubricant in the compressor circulates through the system with the refrigerant. Add lubricant to compres-
sor when replacing any component or after a large gas leakage occurred. It is important to maintain the speci-
fied amount.
If lubricant quantity is not maintained properly, the following malfunctions may result:
●Lack of lubricant: May lead to a seized compressor
●Excessive lubricant: Inadequate cooling (thermal exchange interference)
LUBRICANT
LUBRICANT RETURN OPERATION
Adjust the lubricant quantity according to the test group shown below.
1. CHECK LUBRICANT RETURN OPERATION
Can lubricant return operation be performed?
●A/C system works properly.
●There is no evidence of a large amount of lubricant leakage.
Ye s o r N o
Yes >> GO TO 2.
No >> GO TO 3.
2. PERFORM LUBRICANT RETURN OPERATION, PROCEEDING AS FOLLOWS:
1. Start engine, and set the following conditions:
–Test condition
Engine speed: Idling to 1,200 rpm
A/C or AUTO switch: ON
Blower speed: Max. position
Temp. control: Optional [Set so that intake air temperature is 25 to 30°C (77 to 86°F).]
Intake position: Recirculation (REC)
2. Perform lubricant return operation for about 10 minutes.
3. Stop engine.
CAUTION:
If excessive lubricant leakage is noted, do not perform the lubricant return operation.
>> GO TO 3.
3. CHECK COMPRESSOR
Should the compressor be replaced?
Ye s o r N o
Ye s > > G o t o AT C - 2 1 , "LUBRICANT ADJUSTING PROCEDURE FOR COMPRESSOR REPLACE-
MENT" .
No >> GO TO 4.Name Nissan A/C System Oil Type S
Part number KLH00-PAGS0

ATC-24
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 refrigerant pressure sensor (with QG
engine), throttle position sensor and auto amplifier.
SELF-DIAGNOSTIC SYSTEM
The self-diagnostic system is built into the auto amplifier (LCU) to quickly locate the cause of problems.
Overview of Control systemEJS001Z7
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:
RJIA0687E

TROUBLE DIAGNOSIS
ATC-41
C
D
E
F
G
H
I
K
L
MA
B
AT C
10 L/RMultiplex communication
(Rx) signal
AV → A/C amp.IGN
ON-
11 B/Y Sensor ground IGN
ON-Approx. 0
12 OR Sunload sensorIGN
ON--
17 PU/WWater temperature sen-
sor signalIGN
ONEngine coolant temperature: Approx.
60°C
18 BR/WCompressor feed back
signal (With gasoline
engine)IGN
ONA/C ON-Approx. 0
When refrigerant pres-
sure sensor connector is
disconnected.Approx. 5
20 LMultiplex communication
(CLK) signalIGN
ON-
21 G/YPower supply for mode
door, air mix door and
intake door motorIGN
ON-Approx. 12
22 L/R Compressor ON signalIGN
ONCompressor: ON Approx. 0
Compressor: OFF Approx. 5
24 B GroundIGN
ON-Approx. 0
26 R/B Power supply for BATTIGN
OFF-Approx. 12
27 Y/G Power supply for IGNIGN
ON-Approx. 12
29 LG/B Fan ON signalIGN
ONBlower fan: ON Approx. 0
Blower fan: OFF Approx. 5
33 L/W Power supply for ACCIGN
ON-Approx. 12
34 L/BBlower fan motor feed
back signalIGN
ONFan speed: Manual 1st Approx. 8
35 L/YFan control amp. control
signalIGN
ONFan speed:Manual 1st - 4th speed Approx. 2.5 - 3.5
Manual 5th speed Approx. 9.0 TERMI-
NAL NO.WIRE
COLORITEM CONDITIONVo lta g e
(V)
RJIA0213E
SKIA0056J
HAK0363D

ATC-42
TROUBLE DIAGNOSIS
Self-diagnosis Function
EJS001ZH
DESCRIPTION
The self-diagnostic system diagnoses sensors, door motors, blower motor, etc. by system line. Refer to appli-
cable sections (items) for details. Shifting from usual control to the self-diagnostic system is accomplished by
starting the engine (turning the ignition switch from OFF to ON) and pressing OFF switch for at least 5 sec-
onds. The “OFF” switch must be pressed within 10 seconds after starting the engine (ignition switch is turned
ON). This system will be canceled by either pressing A/C switch or turning the ignition switch OFF. Shifting
from one step to another is accomplished by means of turning temperature dial, as required.
Additionally shifting from STEP 6 to AUXILIARY MECHANISM is accomplished by means of pushing (fan)
UP switch.
RJIA1681E

ATC-70
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.
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 (133°F), 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.
*1AT C - 4 2 , "Self-diagnosis Function"*2AT C - 4 2 , "Self-diagnosis Function",
see No.14.*3AT C - 6 9 , "Blower Motor Circuit"
*4AT C - 5 1 , "Operational Check"*5AT C - 2 9 , "SYMPTOM TABLE"*6 QG engine (With EURO–OBD): EC-
144, "DTC P0117, P0118 ECT SEN-
SOR"
QG engine (Without EURO–OBD):
EC-501, "
DTC P0117, P0118 ECT
SENSOR"
YD engine: EC-84, "DTC 0115
COOLANT TEMP SEN"
RJIA0785E

TROUBLE DIAGNOSIS
ATC-71
C
D
E
F
G
H
I
K
L
MA
B
AT C
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 (133°F), at which time the blower speed will increase to the objective speed.
Start Up From Usual 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).
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 heater & cooling unit. The
fan control amp. receives a gate voltage from the auto amp. to step-
lessly maintain the blower fan motor voltage in the 4 to 12 volt range.
DIAGNOSTIC PROCEDURE FOR BLOWER MOTOR
SYMPTOM: Blower motor operation is malfunctioning under starting
fan speed control.
RJIA0522E
RHA625H
RJIA0786E