Nissan Pathfinder (2008 year). Manual — part 454

HAC-176

< SYMPTOM DIAGNOSIS >

[MANUAL AIR CONDITIONER]

INSUFFICIENT COOLING

Testing must be performed as follows:

Test Reading

INFOID:0000000001366774

Ambient Air Temperature-to-operating Pressure Table

Recirculating-to-discharge Air Temperature Table

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

Recirculation (REC) switch

(Recirculation) set

Blower speed

Max. speed set

Engine speed

Idle speed

Operate the air conditioning system for 10 minutes before taking measurements.

Inside air (Recirculating air) at blower assembly inlet

Discharge air temperature at center ventilator

°

C (

°

F)

Relative humidity

%

Air temperature

°

C (

°

F)

50 - 60

20 (68)

5.3 - 6.5 (42 - 44)

25 (77)

9.7 - 11.5 (49 - 53)

30 (86)

13.8 - 16.3 (57 - 61)

35 (95)

18.0 - 21.2 (64 - 70)

40 (104)

22.2 - 25.7 (72 - 78)

60 - 70

20 (68)

6.5 - 7.7 (44 - 46)

25 (77)

11.5 - 13.3 (53 - 56)

30 (86)

16.3 - 18.8 (61 - 66)

35 (95)

21.2 - 24.0 (70 - 75)

40 (104)

25.7 - 29.2 (78 - 85)

Ambient air

High-pressure (Discharge side)

kPa (kg/cm

2

, psi)

Low-pressure (Suction side)

kPa (kg/cm

2

, psi)

Relative humidity

%

Air temperature

°

C (

°

F)

50 - 70

20 (68)

680 - 840

(6.94 - 8.57, 98.6 - 121.8)

160 - 198

(1.63 - 2.02, 23.2 - 28.7)

25 (77)

800 - 985

(8.16 - 10.05, 116.0 - 142.8)

198 - 245

(2.02 - 2.50, 28.7 - 35.5)

30 (86)

940 - 1,150

(9.59 - 11.73, 136.3 - 166.8)

225 - 278

(2.30 - 2.84, 32.6 - 40.3)

35 (95)

1,160 - 1,410

(11.83 - 14.38, 168.2 - 204.5)

273 - 335

(2.78 - 3.42, 39.6 - 48.6)

40 (104)

1,325 - 1,620

(13.52 - 16.52, 192.1 - 234.9)

325 - 398

(3.32 - 4.06, 47.1 - 57.7)

INSUFFICIENT COOLING

HAC-177

< SYMPTOM DIAGNOSIS >

[MANUAL AIR CONDITIONER]

C

D

E

F

G

H

J

K

L

M

A

B

HAC

N

O

P

Ambient Air Temperature-to-operating Pressure Table

Trouble Diagnoses for Unusual Pressure

INFOID:0000000001366775

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

Inside air (Recirculating air) at blower assembly inlet

Discharge air temperature at center ventilator

°

C (

°

F)

Relative humidity

%

Air temperature

°

C (

°

F)

50 - 60

20 (68)

9.9 - 13.9 (50 - 57)

25 (77)

14.6 - 18.6 (58 - 65)

30 (86)

16.8 - 21.8 (62 - 71)

35 (95)

21.1 - 27.1 (70 - 81)

40 (104)

25.3 - 31.5 (78 - 89)

60 - 70

20 (68)

11.4 - 15.2 (53 - 59)

25 (77)

15.5 - 20.0 (60 - 68)

30 (86)

19.9 - 25.0 (68 - 77)

35 (95)

24.5 - 29.6 (76 - 85)

40 (104)

28.7 - 34.9 (84 - 95)

Ambient air

High-pressure (Discharge side)

kPa (kg/cm

2

, psi)

Low-pressure (Suction side)

kPa (kg/cm

2

, psi)

Relative humidity

%

Air temperature

°

C (

°

F)

50 - 70

20 (68)

1020 - 1250

(10.4 - 12.7, 147.9 - 181.3)

160 - 190

(1.63 - 1.94, 23.2 - 27.6)

25 (77)

1236 - 1510

(12.6 - 15.4, 179.2 - 219)

206 - 245

(2.1 - 2.5, 29.9 - 35.6)

30 (86)

1569 - 1,922

(16.0 - 19.6, 227.6 - 278.8)

265 - 324

(2.7 - 3.3, 38.4 - 46.9)

35 (95)

1,697 - 2079

(17.3 - 21.2, 246.1 - 301.5)

304 - 363

(3.1 - 3.7, 44.1 - 52.6)

40 (104)

1971 - 2403

(20.1 - 24.5, 285.9 - 348.5)

373 - 451

(3.8 - 4.6, 54.0 - 65.4)

HAC-178

< SYMPTOM DIAGNOSIS >

[MANUAL AIR CONDITIONER]

INSUFFICIENT COOLING

High-pressure Side is Too High and Low-pressure Side is Too Low

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

Both high- and low-pressure sides
are too high.

Pressure is reduced soon af-
ter water is splashed on con-
denser.

Excessive refrigerant charge in
refrigeration cycle

Reduce refrigerant until speci-
fied pressure is obtained.

Air suction by cooling fan is in-
sufficient.

Insufficient condenser cooling
performance

↓

1.

Condenser fins are
clogged.

2.

Improper fan rotation of
cooling fan

• Clean condenser.
• Check and repair cooling fan

if necessary.

• Low-pressure pipe is not

cold.

• When compressor is

stopped high-pressure val-
ue quickly drops by approx-

imately 196 kPa (2 kg/cm

2

,

28 psi). It then decreases
gradually thereafter.

Poor heat exchange in con-
denser
(After compressor operation
stops, high-pressure decreas-
es too slowly.)

↓

Air in refrigeration cycle

Evacuate and recharge system.

Engine tends to overheat.

Engine cooling systems mal-
function.

Check and repair engine cool-
ing system.

• An area of the low-pressure

pipe is colder than areas
near the evaporator outlet.

• Plates are sometimes cov-

ered with frost.

• Excessive liquid refrigerant

on low-pressure side

• Excessive refrigerant dis-

charge flow

• Expansion valve is open a lit-

tle compared with the speci-
fication.

↓

Improper expansion valve ad-
justment

Replace 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 lo-
cated between compressor
and condenser are clogged or
crushed.

• Check and repair or replace

malfunctioning parts.

• Check oil for contamination.

AC360A

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 be-
tween high- and low-pressure
sides.

Compressor pressure opera-
tion is improper.

↓

Damaged inside compressor
packings.

Replace compressor.

AC356A

INSUFFICIENT COOLING

HAC-179

< SYMPTOM DIAGNOSIS >

[MANUAL AIR CONDITIONER]

C

D

E

F

G

H

J

K

L

M

A

B

HAC

N

O

P

Low-pressure Side Sometimes Becomes Negative

Low-pressure Side Becomes Negative

Gauge indication

Refrigerant cycle

Probable cause

Corrective action

Both high- and low-pressure sides
are too low.

• There is a big temperature

difference between liquid
tank outlet and inlet. Outlet
temperature is extremely
low.

• Liquid tank inlet and expan-

sion valve are frosted.

Liquid tank inside is slightly
clogged.

• Replace liquid tank.
• Check oil for contamination.

• Temperature of expansion

valve inlet is extremely low
as compared with areas
near liquid tank.

• Expansion valve inlet may

be frosted.

• Temperature difference oc-

curs somewhere in high-
pressure side.

High-pressure pipe located be-
tween liquid tank and expan-
sion valve is clogged.

• Check and repair malfunc-

tioning parts.

• Check oil for contamination.

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 to XX-XX, "*****".

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.

• Remove foreign particles by

using compressed air.

• Check oil for contamination.

An area of the low-pressure
pipe is colder than areas near
the evaporator outlet.

Low-pressure pipe is clogged
or crushed.

• Check and repair malfunc-

tioning parts.

• Check oil for contamination.

Air flow volume is too low.

Evaporator is frozen.

• Check intake sensor circuit.

Refer to XX-XX, "*****".

• Replace compressor.
• Repair evaporator fins.
• Replace evaporator.
• Refer to XX-XX, "*****".

AC353A

Gauge indication

Refrigerant cycle

Probable cause

Corrective action

Low-pressure side sometimes be-
comes negative.

• Air conditioning system does

not function and does not cy-
clically cool the compart-
ment air.

• The system constantly func-

tions for a certain period of
time after compressor is
stopped and restarted.

Refrigerant does not discharge
cyclically.

↓

Moisture is frozen at expan-
sion valve outlet and inlet.

↓

Water is mixed with refrigerant.

• Drain water from refrigerant

or replace refrigerant.

• Replace liquid tank.

AC354A

HAC-180

< SYMPTOM DIAGNOSIS >

[MANUAL AIR CONDITIONER]

INSUFFICIENT COOLING

Gauge indication

Refrigerant cycle

Probable cause

Corrective action

Low-pressure side becomes nega-
tive.

Liquid tank or front/rear side of
expansion valve

′

s pipe is frost-

ed 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.
• If water is the cause, initially

cooling is okay. Then the wa-
ter freezes causing a block-
age. Drain water from
refrigerant or replace refrig-
erant.

• If due to foreign particles, re-

move expansion valve and
remove the particles with dry
and compressed air (not
shop air).

• If either of the above meth-

ods cannot correct the mal-
function, replace expansion
valve.

• Replace liquid tank.
• Check oil for contamination.

AC362A

INSUFFICIENT HEATING

HAC-181

< SYMPTOM DIAGNOSIS >

[MANUAL AIR CONDITIONER]

C

D

E

F

G

H

J

K

L

M

A

B

HAC

N

O

P

INSUFFICIENT HEATING

Component Function Check

INFOID:0000000001366776

SYMPTOM: Insufficient heating

INSPECTION FLOW

1.

CONFIRM SYMPTOM BY PERFORMING OPERATIONAL CHECK - TEMPERATURE INCREASE

1.

Rotate blower control dial clockwise.

2.

Turn the temperature control dial clockwise to maximum heat.

3.

Check for hot air at discharge air outlets.

Can the symptom be duplicated?

YES

>> GO TO 2.

NO

>> Perform complete operational check (front). Refer to XX-XX, "*****".

2.

CHECK FOR SERVICE BULLETINS

Check for any service bulletins.

>> GO TO 3.

3.

CHECK ENGINE COOLING SYSTEM

1.

Check for proper engine coolant level. Refer to XX-XX, "*****".

2.

Check hoses for leaks or kinks.

3.

Check radiator cap. Refer to XX-XX, "*****".

4.

Check for air in cooling system.

>> GO TO 4.

4.

CHECK AIR MIX DOOR OPERATION

Check the operation of the air mix door.
OK or NG

OK

>> GO TO 5.

NG

>> Check the air mix door motor circuit. Refer to XX-XX, "*****".

5.

CHECK AIR DUCTS

Check for disconnected or leaking air ducts.

OK or NG

OK

>> GO TO 6.

NG

>> Repair all disconnected or leaking air ducts.

6.

CHECK HEATER HOSE TEMPERATURES

1.

Start engine and warm it up to normal operating temperature.

2.

Touch both the inlet and outlet heater hoses.

OK or NG

OK

>> Hot inlet hose and a warm outlet hose: GO TO 7.

NG

>> Both hoses warm: GO TO 8.

7.

CHECK ENGINE COOLANT SYSTEM

Check engine coolant temperature sensor. Refer to XX-XX, "*****".

OK or NG

OK

>> System OK.

NG

>> Repair or replace as necessary. Retest.

8.

CHECK HEATER HOSES

Check heater hoses for proper installation.
OK or NG

HAC-182

< SYMPTOM DIAGNOSIS >

[MANUAL AIR CONDITIONER]

INSUFFICIENT HEATING

OK

>> System OK.

NG

>> 1.

Back flush heater core.

2.

Drain the water from the system.

3.

Refill system with new engine coolant. Refer to XX-XX, "*****".

4.

GO TO 9 to retest.

9.

CHECK HEATER HOSE TEMPERATURES

1.

Start engine and warm it up to normal operating temperature.

2.

Touch both the inlet and outlet heater hoses.

OK or NG

OK

>> System OK.

NG

>> Replace heater core. Refer to XX-XX, "*****".

NOISE

HAC-183

< SYMPTOM DIAGNOSIS >

[MANUAL AIR CONDITIONER]

C

D

E

F

G

H

J

K

L

M

A

B

HAC

N

O

P

NOISE

Component Function Check

INFOID:0000000001366777

SYMPTOM: Noise

INSPECTION FLOW

WJIA1972E