Nissan Titan. Manual - part 395

INSUFFICIENT COOLING

HAC-85

< SYMPTOM DIAGNOSIS >

[AUTOMATIC AIR CONDITIONER]

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*1

HA-24, "Checking System for Leaks 
Using the Fluorescent Dye Leak De-
tector"

*2

HA-33, "Removal and Installation"

*3

HAC-86, "Performance Chart"

*4

HAC-87, "Trouble Diagnoses for Ab-
normal Pressure"

*5

HAC-28, "Air Mix Door Motor (Driver) 
Component Function Check"

AWIIA0999GB

HAC-86

< SYMPTOM DIAGNOSIS >

[AUTOMATIC AIR CONDITIONER]

INSUFFICIENT COOLING

Performance Chart

INFOID:0000000009882490

TEST CONDITION

Testing must be performed as follows:

*1

HA-33, "Removal and Installation"

*2

HAC-44, "Front Blower Motor Com-
ponent Function Check"

*3

HA-33, "Removal and Installation"

*4

EM-14, "Checking Drive Belts"

*5

HA-31, "Removal and Installation"

AWIIA1000GB

INSUFFICIENT COOLING

HAC-87

< SYMPTOM DIAGNOSIS >

[AUTOMATIC AIR CONDITIONER]

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Recirculating-to-discharge Air Temperature Table

Ambient Air Temperature-to-operating Pressure Table

Trouble Diagnoses for Abnormal Pressure

INFOID:0000000009882491

Whenever 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 (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).

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)

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-88

< SYMPTOM DIAGNOSIS >

[AUTOMATIC AIR CONDITIONER]

INSUFFICIENT COOLING

Both High- and Low-pressure Sides are Too High

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

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