NISSAN NAVARA 2005 Repair Workshop Manual

TROUBLE DIAGNOSIS
ATC-97
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AT C
TROUBLE DIAGNOSES FOR UNUSUAL PRESSURE
Whenever system¢s high and/or low side pressure is unusual, diagnose using a manifold gauge. The marker
above the gauge scale in the following tables indicates the standard (usual) pressure range. Since the stan-
dard (usual) pressure, however, differs from vehicle to vehicle, refer to above table (Ambient air temperature-
to-operating pressure table).
Both High- and Low-pressure Sides are Too High
High-pressure Side is Too High and Low-pressure Side is Too Low
Gauge indication Refrigerant cycle Probable cause Corrective action
Both high- and low-pressure sides
are too high.Pressure is reduced soon
after water is splashed on
condenser.Excessive refrigerant charge
in refrigeration cycleReduce refrigerant until speci-
fied pressure is obtained.
Air suction by cooling fan is
insufficient.Insufficient condenser cooling
performance
¯
1. Condenser fins are clogged.
2. Improper fan rotation of
cooling fan
lClean condenser.
lCheck and repair cooling fan
if necessary.
lLow-pressure pipe is not
cold.
lWhen 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 engine cool-
ing system.
lAn area of the low-pres-
sure pipe is colder than
areas near the evaporator
outlet.
lPlates are sometimes cov-
ered with frost.
lExcessive liquid refrigerant
on low-pressure side
lExcessive refrigerant dis-
charge flow
lExpansion valve is open a
little compared with the
specification.
¯
Improper expansion valve
adjustmentReplace expansion valve.
AC359A
Gauge indication Refrigerant cycle Probable cause Corrective action
High-pressure side is too high and
low-pressure side is too low.
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.
lCheck and repair or replace
malfunctioning parts.
lCheck lubricant for contami-
nation.
AC360A

ATC-98
TROUBLE DIAGNOSIS
High-pressure Side is Too Low and Low-pressure Side is Too High
Both High- and Low-pressure Sides are Too Low
Gauge indication Refrigerant cycle Probable cause Corrective action
High-pressure side is too low and
low-pressure side is too high.High- and low-pressure sides
become equal soon after com-
pressor operation stops.Compressor pressure opera-
tion is improper.
¯
Damaged inside compressor
packings.Replace compressor.
No temperature difference
between high- and low-pres-
sure sides.Compressor pressure opera-
tion is improper.
¯
Damaged inside compressor
packings.Replace compressor.
AC356A
Gauge indication Refrigerant cycle Probable cause Corrective action
Both high- and low-pressure sides
are too low.
lThere is a big temperature
difference between liquit
tand outlet and inlet. Outlet
temperature is extremely
low.
lLiquid tank inlet and expan-
sion valve are frosted.Liquid tank inside is slightly
clogged.
lReplace liquid tank.
lCheck lubricant for contami-
nation.
lTemperature of expansion
valve inlet is extremely low
as compared with areas
near liquid tank.
lExpansion valve inlet may
be frosted.
lTemperature difference
occurs somewhere in high-
pressure side.High-pressure pipe located
between liquit tank and expan-
sion valve is clogged.
lCheck and repair malfunc-
tioning parts.
lCheck lubricant for contami-
nation.
Expansion valve and liquid
tank are warm or only cool
when touched.Low refrigerant charge.
¯
Leaking fittings or compo-
nents.Check refrigerant system for
leaks. Refer toATC-150,
"Checking for Refrigerant
Leaks".
There is a big temperature dif-
ference between expansion
valve inlet and outlet while the
valve itself is frosted.Expansion valve closes a little
compared with the specifica-
tion.
¯
1. Improper expansion valve
adjustment.
2. Malfunctioning expansion
valve.
3. Outlet and inlet may be
clogged.
lRemove foreign particles by
using compressed air.
lCheck lubricant for contami-
nation.
An area of the low-pressure
pipe is colder than areas near
the evaporator outlet.Low-pressure pipe is clogged
or crushed.
lCheck and repair malfunc-
tioning parts.
lCheck lubricant for contami-
nation.
Air flow volume is too low. Evaporator is frozen.
lCheck intake sensor circuit.
Refer toAT C - 11 4 , "
Intake
Sensor Circuit".
lReplace compressor.
lRepair evaporator fins.
lReplace evaporator.
lRefer toAT C - 8 0 , "Blower
Motor Circuit".
AC353A

TROUBLE DIAGNOSIS
ATC-99
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AT C
Low-pressure Side Sometimes Becomes Negative
Low-pressure Side Becomes Negative
Gauge indication Refrigerant cycle Probable cause Corrective action
Low-pressure side sometimes
becomes negative.
lAir conditioning system
does not function and does
not cyclically cool the com-
partment air.
lThe system constantly func-
tions for a certain period of
time after compressor is
stopped and restarted.Refrigerant does not dis-
charge cyclically.
¯
Moisture is frozen at expan-
sion valve outlet and inlet.
¯
Water is mixed with refriger-
ant.
lDrain water from refrigerant
or replace refrigerant.
lReplace liquid tank.
AC354A
Gauge indication Refrigerant cycle Probable cause Corrective action
Low-pressure side becomes nega-
tive.
Liquid tank or front/rear side of
expansion valve¢spipeis
frosted or dewed.High-pressure side is closed
and refrigerant does not flow.
¯
Expansion valve or liquid tank
is frosted.Leave the system at rest until
no frost is present. Start it
again to check whether or not
the malfunction is caused by
water or foreign particles.
lIf water is the cause, initially
cooling is okay. Then the
water freezes causing a
blockage. Drain water from
refrigerant or replace refrig-
erant.
lIf due to foreign particles,
remove expansion valve
and remove the particles
with dry and compressed air
(not shop air).
lIf either of the above meth-
ods cannot correct the mal-
function, replace expansion
valve.
lReplace liquid tank.
lCheck lubricant for contami-
nation.
AC362A

ATC-100
TROUBLE DIAGNOSIS
Insufficient Heating
EJS006BS
SYMPTOM: Insufficient heating
INSPECTION FLOW
*1ATC-57, "Operational Check".*2AT C - 6 8 , "Air Mix Door Motor Circuit".*3ATC-55, "A/C System Self-diagno-
sis Function".
*4ATC-55, "
A/C System Self-diagnosis
Function".*5AT C - 8 0 , "
Blower Motor Circuit".*6EC-103, "DTC P0117, P0118 ECT
SENSOR".
*7CO-7, "
Changing Engine Coolant".*8CO-13, "Checking Reservoir Tank
Cap".
MJIB0350E

TROUBLE DIAGNOSIS
ATC-101
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AT C
NoiseEJS006BT
SYMPTOM: Noise
INSPECTION FLOW
WJIA0473E

ATC-102
TROUBLE DIAGNOSIS
*1ATC-143, "REMOVAL".*2ATC-144, "INSTALLATION".*3AT C - 2 4 , "Maintenance of Lubricant
Quantity in Compressor".
*4ATC-57, "
Operational Check".*5EM-12, "Checking Drive Belts".

TROUBLE DIAGNOSIS
ATC-103
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AT C
Self-diagnosisEJS006BU
SYMPTOM: Self-diagnosis cannot be performed.
INSPECTION FLOW
*1AT C - 6 0 , "Power Supply and Ground
Circuit for Front Air Control".*2ATC-105, "
Ambient Sensor Circuit".*3ATC-108, "In-vehicle Sensor Circuit".
*4AT C - 11 2 , "
Optical Sensor Circuit".*5ATC-114, "Intake Sensor Circuit".*6AT C - 6 8 , "Air Mix Door Motor Circuit".
*7AT C - 5 7 , "
Operational Check".*8ATC-35, "SYMPTOM TABLE".
MJIB0351E

ATC-104
TROUBLE DIAGNOSIS
Memory Function
EJS006BV
SYMPTOM: Memory function does not operate.
INSPECTION FLOW
*1ATC-60, "Power Supply and Ground
CircuitforFrontAirControl".*2ATC-57, "
Operational Check".*3AT C - 5 5 , "A/C System Self-diagnosis
Function".
MJIB0332E

TROUBLE DIAGNOSIS
ATC-105
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Ambient Sensor CircuitEJS006BW
COMPONENT DESCRIPTION
Ambient Sensor
Ambient sensor is attached to the radiator core support (left side). It
detects ambient temperature and converts it into a resistance value
which is then input into the front air control.
AMBIENT TEMPERATURE INPUT PROCESS
The front air control includes a processing circuit for ambient sensor input. However, when the temperature
detected by ambient sensor increases quickly, the processing circuit retards the front air control function. It
only allows the front air control to recognize an ambient temperature increase of 0.33°C(0.6°F) per 100 sec-
onds.
This prevents constant adjustments due to momentary conditions, such as stopping after high speed driving.
Although the actual ambient temperature has not changed, the temperature detected by ambient sensor will
increase. This is because the heat from the engine compartment can radiate to the front grille area, location of
ambient sensor .
DIAGNOSTIC PROCEDURE FOR AMBIENT SENSOR
SYMPTOM: Ambient sensor circuit is open or shorted. (40 or 41 is
indicated on front air control as a result of conducting the front air
control self-diagnosis)
1.CHECK VOLTAGE BETWEEN AMBIENT SENSOR AND GROUND
1. Disconnect ambient sensor connector.
2. Turn ignition switch ON.
3. Check voltage between ambient sensor harness connector E48
terminal 4 and ground.
OK or NG
OK >> GO TO 2.
NG >> GO TO 4.
MJIB0168E
MJIB0090E
4 - Ground : Approx. 5V
MJIB0091E

ATC-106
TROUBLE DIAGNOSIS
2.CHECK CIRCUIT CONTINUITY BETWEEN AMBIENT SENSOR AND FRONT AIR CONTROL
1. Turn ignition switch OFF.
2. Disconnect front air control connector.
3. Check continuity between ambient sensor harness connector
E48 terminal 3 and front air control harness connector M60 ter-
minal 13.
OK or NG
OK >> GO TO 3.
NG >> Repair harness or connector.
3.CHECK AMBIENT SENSOR
Refer toATC-107, "
Ambient Sensor".
OK or NG
OK >> 1. Replace front air control.
2. Go to self-diagnosisAT C - 5 5 , "
A/C System Self-diagnosis Function"and perform self-diagno-
sis.
NG >> 1. Replace ambient sensor.
2. Go to self-diagnosisAT C - 5 5 , "
A/C System Self-diagnosis Function"and perform self-diagno-
sis.
4.CHECK CIRCUIT CONTINUITY BETWEEN AMBIENT SENSOR AND FRONT AIR CONTROL
1. Turn ignition switch OFF.
2. Disconnect front air control connector.
3. Check continuity between ambient sensor harness connector
E48 terminal 4 and front air control harness connector M61 ter-
minal 28.
4. Check continuity between ambient sensor harness connector
E48 terminal 4 and ground.
OK or NG
OK >> 1. Replace front air control.
2. Go to self-diagnosisAT C - 5 5 , "
A/C System Self-diagnosis Function"and perform self-diagno-
sis.
NG >> Repair harness or connector.3 - 13 : Continuity should exist.
MJIB0092E
4 - 28 : Continuity should exist.
4 - Ground : Continuity should not exist.
MJIB0093E