Nissan Pathfinder (2006 year). Instruction — part 340

TROUBLE DIAGNOSIS

MTC-73

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MTC

2006 Pathfinder

PERFORMANCE CHART
Test Condition

Testing must be performed as follows:

Test Reading

Recirculating-to-discharge Air Temperature Table

Ambient Air Temperature-to-operating Pressure 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)

MTC-74

TROUBLE DIAGNOSIS

2006 Pathfinder

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 cycle

Reduce 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

●

Clean condenser.

●

Check and repair cooling fan
if necessary.

●

Low-pressure pipe is not
cold.

●

When 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 cycle

Evacuate and recharge sys-
tem.

Engine tends to overheat.

Engine cooling systems mal-
function.

Check and repair engine cool-
ing system.

●

An area of the low-pres-
sure 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
little compared with the
specification.

↓

Improper expansion valve
adjustment

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
located between compressor
and condenser are clogged or
crushed.

●

Check and repair or replace
malfunctioning parts.

●

Check oil for contamination.

AC360A

TROUBLE DIAGNOSIS

MTC-75

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MTC

2006 Pathfinder

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.

●

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
occurs somewhere in high-
pressure side.

High-pressure pipe located
between liquid tank and
expansion 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

ATC-170,

"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.

●

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

ATC-125, "Intake

Sensor Circuit"

.

●

Replace compressor.

●

Repair evaporator fins.

●

Replace evaporator.

●

Refer to

ATC-75, "Front

Blower Motor Circuit"

.

AC353A

MTC-76

TROUBLE DIAGNOSIS

2006 Pathfinder

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.

●

Air conditioning system
does not function and does
not cyclically cool the com-
partment air.

●

The 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.

●

Drain water from refrigerant
or replace refrigerant.

●

Replace 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

′

s pipe is

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.

●

If water is the cause, initially
cooling is okay. Then the
water freezes causing a
blockage. Drain water from
refrigerant or replace refrig-
erant.

●

If due to foreign particles,
remove 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

TROUBLE DIAGNOSIS

MTC-77

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MTC

2006 Pathfinder

Insufficient Heating

EJS004RT

SYMPTOM: Insufficient heating

INSPECTION FLOW

*1

ATC-53, "Operational Check (Front)"

*2

ATC-63, "Air Mix Door Motor Circuit"

*3

EC-207, "DTC P0117, P0118 ECT
SENSOR"

*4

MA-13, "Changing Engine Coolant"

*5

CO-10, "CHECKING RESERVOIR
CAP"

*6

CO-10, "Changing Engine Coolant"

*7

MTC-89, "HEATER CORE"

WJIA1983E

MTC-78

TROUBLE DIAGNOSIS

2006 Pathfinder

Noise

EJS004RU

SYMPTOM: Noise

INSPECTION FLOW

WJIA1972E

TROUBLE DIAGNOSIS

MTC-79

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MTC

2006 Pathfinder

*1

ATC-159, "REMOVAL"

*2

ATC-160, "INSTALLATION"

*3

ATC-22, "Maintenance of Oil Quan-
tity in Compressor"

*4

ATC-53, "Operational Check (Front)"

*5

MA-13, "Checking Drive Belts"

MTC-80

TROUBLE DIAGNOSIS

2006 Pathfinder

Intake Sensor Circuit

EJS004RV

COMPONENT DESCRIPTION
Intake Sensor

The intake sensor is located on top of the heater and cooling unit
assembly next to the A/C evaporator cover. It converts temperature
of air after it passes through the evaporator into a resistance value
which is then input to the front air control.

DIAGNOSTIC PROCEDURE FOR INTAKE SENSOR

SYMPTOM: Intake sensor circuit is open or shorted.

1.

CHECK VOLTAGE BETWEEN INTAKE SENSOR AND GROUND

1.

Disconnect intake sensor connector.

2.

Turn ignition switch ON.

3.

Check voltage between intake sensor harness connector M146
terminal 2 and ground.

OK or NG

OK

>> GO TO 2.

NG

>> GO TO 4.

2.

CHECK CIRCUIT CONTINUITY BETWEEN INTAKE SENSOR AND FRONT AIR CONTROL

1.

Turn ignition switch OFF.

2.

Disconnect front air control connector.

3.

Check continuity between intake sensor harness connector
M146 terminal 1 and front air control harness connector M49 ter-
minal 13.

OK or NG

OK

>> GO TO 3.

NG

>> Repair harness or connector.

WJIA1155E

WJIA1156E

2 - Ground

: Approx. 5V

WJIA1278E

1 - 13

: Continuity should exist.

WJIA1157E