engine INFINITI QX4 2001 Factory Service Manual

7 STEP 4 - OPERATION OF EACH ACTUATOR IS CHECKED
Press(HOT) switch.
Engine running.
Press DEF switch, code No. of each actuator test is indicated on the display.
RHA495A
©GO TO 8.
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TROUBLE DIAGNOSES
Self-diagnosis (Cont'd)
HA-47

INTRODUCTION AND GENERAL DESCRIPTIONNBHA0021S04The self-diagnostic system diagnoses sensors, door motors, blower motor, etc. by system line. Refer to appli-
cable sections (items) for details. Shifting from normal control to the self-diagnostic system is accomplished
by starting the engine (turning the ignition switch from ªOFFº to ªONº) and pressing ª
º switch for at least
5 seconds. The ª
º switch must be pressed within 10 seconds after starting the engine (ignition switch is
turned ªONº). This system will be canceled by either pressing
(AUTO) switch or turning the ignition switch
ªOFFº. Shifting from one step to another is accomplished by means of turning temperature dial, as required.
Additionally shifting from STEP 5 to AUXILIARY MECHANISM is accomplished by means of pushing
(fan)
UP switch.
With Navigation SystemNBHA0021S0401
RHA859H
TROUBLE DIAGNOSES
Self-diagnosis (Cont'd)
HA-54

STEP-BY-STEP PROCEDURENBHA0021S05With Navigation SystemNBHA0021S0501
1 SET IN SELF-DIAGNOSTIC MODE
1. Turn ignition switch ON.
2. Set in self-diagnostic mode as follows. Within 10 seconds after starting engine (ignition switch is turned ªONº.), press
switch for at least 5 seconds.
©GO TO 2.
2 STEP 1 - ALL LEDs AND DISPLAY SCREEN ARE CHECKED
When switch's LED and display are functioning properly in STEP-1, LED and display will come on.
RHA860H
OK or NG
OK©GO TO 3.
NG©Malfunctioning
switch, LED or fluorescent display tube.
Go to ªMain Power Supply and Ground Circuit Checkº, HA-72.
3 VERIFY ADVANCE TO SELF-DIAGNOSIS STEP 2
1. Turn temperature dial clockwise.
2. Does advance to self-diagnosis STEP 2?
YesorNo
Ye s©GO TO 4.
No©Malfunctioning temperature dial.
Check Display & NAVI control unit.
4 VERIFY RETURN TO SELF-DIAGNOSIS STEP 1
1. Turn temperature dial counterclockwise.
2. Does return to self-diagnosis STEP 1?
YesorNo
Ye s©GO TO 5.
No©Malfunctioning temperature dial.
Check Display & NAVI control unit.
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TROUBLE DIAGNOSES
Self-diagnosis (Cont'd)
HA-55

7 STEP 4 - OPERATION OF EACH ACTUATOR IS CHECKED
Turn temperature dial clockwise.
Engine running.
Press DEF switch, code No. of each actuator test is indicated on the display.
RHA495A
©GO TO 8.
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TROUBLE DIAGNOSES
Self-diagnosis (Cont'd)
HA-57

Operational CheckNBHA0019The purpose of the operational check is to confirm that the system
operates properly.
CONDITIONS:NBHA0019S01IEngine running and at normal operating temperature.
RHA864H
RHA335HA
PROCEDURE:NBHA0019S021. Check Memory FunctionNBHA0019S02011. Set the temperature 85ÉF or 32ÉC.
2. Press OFF switch.
3. Turn the ignition off.
4. Turn the ignition on.
5. Press the AUTO switch.
6. Confirm that the set temperature remains at previous tempera-
ture.
7. Press OFF switch.
If NG, go to trouble diagnosis procedure for memory function (HA-
126).
If OK, continue with next check.
RHA457GA
RHA329HA
2. Check BlowerNBHA0019S02021. Press fan switch (up side) one time.
Blower should operate on low speed.
The fan symbol should have one blade lit
.
2. Press fan switch (up side) one more time, and continue check-
ing blower speed and fan symbol until all speeds are checked.
3. Leave blower on MAX speed
.
If NG, go to trouble diagnosis procedure for blower motor (HA-95).
If OK, continue with next check.
TROUBLE DIAGNOSES
Operational Check
HA-66

SYSTEM DESCRIPTION=NBHA0062Component partsNBHA0062S01Fan speed control system components are:
1) Auto amp.
2) Fan control amp.
3) A/C LAN system (PBR built-in mode door motor and air mix door motor)
4) In-vehicle sensor
5) Ambient sensor
6) Sunload sensor
7) Intake sensor
System OperationNBHA0062S02
SHA006FF
Automatic ModeNBHA0062S03In the automatic mode, the blower motor speed is calculated by the automatic amplifier based on inputs from
the PBR, in-vehicle sensor, sunload sensor, intake sensor and ambient sensor. The blower motor applied
voltage ranges from approximately 5 volts (lowest speed) to 12 volts (highest speed).
The control blower speed (in the range of 5 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 ControlNBHA0062S04Start Up From ªCOLD SOAKº Condition (Automatic mode)NBHA0062S0401In a cold start up condition where the engine coolant temperature is below 50ÉC (122ÉF), the blower will not
operate for a short period of time (up to 126 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 126 seconds as described above.
After this delay, the blower will operate at low speed until the engine coolant temperature rises above 55ÉC
(131ÉF), at which time the blower speed will increase to the objective speed.
Start Up From Normal or ªHOT SOAKº Condition (Automatic mode)
NBHA0062S0402The blower will begin operation momentarily after the AUTO button is pushed. The blower speed will gradu-
ally rise to the objective speed over a time period of 3 seconds or less (actual time depends on the objective
blower speed).
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TROUBLE DIAGNOSES
Blower Motor (Cont'd)
HA-97

PERFORMANCE CHARTNBHA0031Test ConditionNBHA0031S01Testing must be performed as follows:
Vehicle location Indoors or in the shade (in a well-ventilated place)
Doors Closed
Door window Open
Hood Open
TEMP. Max. COLD
Mode switch
(Ventilation) set
REC switch
(Recirculation) set
(blower) speed Max. speed set
Engine speed Idle speed
Operate the air conditioning system for 10 minutes before taking measurements.
Test ReadingNBHA0031S02Recirculating-to-discharge Air Temperature TableNBHA0031S0201
Inside air (Recirculating air) at blower assembly inlet
Discharge air temperature at center ventilator
ÉC (ÉF) Relative humidity
%Air temperature
ÉC (ÉF)
50-6025 (77) 6.0 - 9.0 (43 - 48)
30 (86) 10.0 - 13.6 (50 - 56)
35 (95) 15.2 - 19.5 (59 - 67)
40 (104) 22.5 - 27.1 (73 - 81)
60-7025 (77) 9.0 - 12.2 (48 - 54)
30 (86) 13.6 - 17.2 (56 - 63)
35 (95) 19.5 - 23.7 (67 - 75)
40 (104) 27.1 - 32.3 (81 - 90)
Ambient Air Temperature-to-operating Pressure TableNBHA0031S0202
Ambient air
High-pressure (Discharge side)
kPa (kg/cm
2, psi)Low-pressure (Suction side)
kPa (kg/cm2, psi) Relative humidity
%Air temperature
ÉC (ÉF)
50-7025 (77)1,226 - 1,638
(12.5 - 16.7, 178 - 237)172 - 250 (1.75 - 2.55, 25 - 36)
30 (86)1,422 - 1,883
(14.5 - 19.2, 206 - 273)196 - 275 (2.0 - 2.8, 28 - 40)
35 (95)1,657 - 2,187
(16.9 - 22.3, 240 - 317)231 - 309 (2.35 - 3.15, 33 - 45)
40 (104)1,922 - 2,501
(19.6 - 25.5, 279 - 363)280 - 373 (2.85 - 3.8, 41 - 54)
TROUBLE DIAGNOSES FOR ABNORMAL PRESSURENBHA0032Whenever system's high and/or low side pressure is abnormal, diagnose using a manifold gauge. The marker
above the gauge scale in the following tables indicates the standard (normal) pressure range. Since the stan-
dard (normal) pressure, however, differs from vehicle to vehicle, refer to HA-116 (ªAmbient air temperature-
to-operating pressure tableº).
TROUBLE DIAGNOSES
Insufficient Cooling (Cont'd)
HA-116

Both High- and Low-pressure Sides are Too High.NBHA0032S01
Gauge indication Refrigerant cycle Probable cause Corrective action
Both high- and low-pressure sides
are too high.
AC359A
IPressure is reduced soon
after water is splashed on
condenser.Excessive refrigerant charge
in refrigeration cycleReduce refrigerant until
specified pressure is
obtained.
Air suction by cooling fan is
insufficient.Insufficient condenser cool-
ing performance
"
1. Condenser fins are
clogged.
2. Improper fan rotation of
cooling fanIClean condenser.
ICheck and repair cooling
fan as necessary.
ILow-pressure pipe is not
cold.
IWhen compressor is
stopped high-pressure
value quickly drops by
approximately 196 kPa (2
kg/cm
2, 28 psi). It then
decreases gradually there-
after.Poor heat exchange in con-
denser
(After compressor operation
stops, high pressure
decreases too slowly.)
"
Air in refrigeration cycleEvacuate repeatedly and
recharge system.
Engine tends to overheat. Engine cooling systems mal-
function.Check and repair each
engine cooling system.
IAn area of the low-pres-
sure pipe is colder than
areas near the evaporator
outlet.
IPlates are sometimes cov-
ered with frost.IExcessive liquid refrigerant
on low-pressure side
IExcessive refrigerant dis-
charge flow
IExpansion valve is open a
little compared with the
specification.
"
1. Improper thermal valve
installation
2. Improper expansion valve
adjustmentReplace expansion valve.
High-pressure Side is Too High and Low-pressure Side is Too Low.NBHA0032S02
Gauge indication Refrigerant cycle Probable cause Corrective action
High-pressure side is too high and
low-pressure side is too low.
AC360A
Upper side of condenser and
high-pressure side are hot,
however, liquid tank is not so
hot.High-pressure tube or parts
located between compressor
and condenser are clogged
or crushed.ICheck and repair or
replace malfunctioning
parts.
ICheck lubricant for con-
tamination.
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TROUBLE DIAGNOSES
Insufficient Cooling (Cont'd)
HA-117

With Navigation SystemNBHA0103S0102
RHA887H
*1: HA-72 *2: HA-66 *3: HA-45
RHA050G
Ambient Sensor Circuit
COMPONENT DESCRIPTIONNBHA0039The ambient sensor is attached in front of the driver's side con-
denser. It detects ambient temperature and converts it into a resis-
tance value which is then input into the auto amplifier.
AMBIENT TEMPERATURE INPUT PROCESSNBHA0040The automatic amplifier includes a ªprocessing circuitº for the ambi-
ent sensor input. However, when the temperature detected by the
ambient sensor increases quickly, the processing circuit retards the
auto amp. function. It only allows the auto amp. to recognize an
ambient temperature increase of 0.33ÉC (0.6ÉF) per 100 seconds.
As an example, consider stopping for a cup of coffee after high
speed driving. Although the actual ambient temperature has not
changed, the temperature detected by the ambient sensor will
increase. This is because the heat from the engine compartment
can radiate to the front grille area, location of the ambient sensor.
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TROUBLE DIAGNOSES
ECON (ECONOMY) Mode (Cont'd)
HA-129

Maintenance of Lubricant Quantity in
Compressor
NBHA0071The lubricant in the compressor circulates through the system with
the refrigerant. Add lubricant to compressor when replacing any
component or after a large gas leakage occurred. It is important to
maintain the specified amount.
If lubricant quantity is not maintained properly, the following mal-
functions may result:
ILack of lubricant: May lead to a seized compressor
IExcessive lubricant: Inadequate cooling (thermal exchange
interference)
LUBRICANTNBHA0071S01Name: Nissan A/C System Oil Type S
Part number: KLH00-PAGS0
CHECKING AND ADJUSTINGNBHA0071S02Adjust the lubricant quantity according to the test group shown
below.
1 CHECK LUBRICANT RETURN OPERATION
Can lubricant return operation be performed?
IA/C system works properly.
IThere is no evidence of a large amount of lubricant leakage.
YesorNo
Ye s©GO TO 2.
No©GO TO 3.
2 PERFORM LUBRICANT RETURN OPERATION, PROCEEDING AS FOLLOWS:
1. Start engine, and set the following conditions:
ITest 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 30ÉC (77 to 86ÉF).]
2.Next item is for V-5 or V-6 compressor. Connect the manifold gauge, and check that the high pressure side
pressure is 588 kPa (6 kg/cm
2, 85 psi) or higher.
If less than the reference level, attach a cover to the front face of the condenser to raise the pressure.
3. Perform lubricant return operation for about 10 minutes.
4. Stop engine.
CAUTION:
If excessive lubricant leakage is noted, do not perform the lubricant return operation.
OK©GO TO 3.
3 CHECK COMPRESSOR
Should the compressor be replaced?
YesorNo
Ye s©Go to ªLubricant Adjustment Procedure for Compressor Replacementº, (HA-148).
No©GO TO 4.
SERVICE PROCEDURE
Maintenance of Lubricant Quantity in Compressor
HA-146