Suzuki Grand Vitara JB627. Manual - part 276

7B-20 Air Conditioning System: 

Visual Inspection

S6JB0B7204007

Visually check the following parts and systems.

A/C System Performance Inspection

S6JB0B7204008

1) Confirm that vehicle and environmental conditions 

are as follows. 
• Vehicle is put indoors. 
• Ambient air temperature is within 15 – 35 

°C (59 – 

95 

°F).

• Relative humidity is within 30 – 70%.
• There is no wind indoors.
• HVAC unit is normal condition.
• There is no air leakage from air ducts.
• Condenser fins are clean.
• Are filter is not clogged with dirt and dust.
• Battery voltage is 12 V or more.
• Radiator cooling fan operates normally.

2) Make sure that high pressure valve (1) and low 

pressure valve (2) of manifold gauge (3) are firmly 
closed.

3) Connect high pressure charging hose (4) to high 

pressure service valve (5) on vehicle, and connect 
low pressure charging hose (6) to low pressure 
service valve (7) on vehicle.

4) Bleed the air in charging hoses by loosening their 

respective nuts on manifold gauge, utilizing the 
refrigerant pressure. When a hiss is heard, 
immediately tighten nut.

CAUTION

!

 

Do not interchange high and low pressure 
charging hoses by mistake.

 

Inspection Item

Correction

• Refrigerant ---- leakage and amount
• A/C pipe or hose ---- disconnection, looseness and 

deterioration

• A/C compressor drive belt ---- looseness and damage
• Battery ---- fluid level and corrosion of terminal
• Connectors of electric wire harness ---- disconnection and 

friction

• Fuses ---- burning
• Parts ---- installation and damage
• Other parts that can be checked visually

Refer to “A/C Compressor Drive Belt Inspection 
and Adjustment”.

3

7

4

1

2

6

5

I5JB0A720010-01

Air Conditioning System:  7B-21

5) Warm up engine to normal operating temperature 

(engine coolant temperature at 80 – 90 

°C (176 – 

194 

°F)) and keep it at specified idle speed.

6) Operate A/C at the following conditions.

• A/C switch at ON position
• Blower speed selector at max position
• Air flow selector at “VENT” position
• Temperature selector at max cool position
• Vehicle door at all open
• Air inlet door at recirculation position

7) Wait for ten minutes to stabilize A/C operation.
8) Keep all windows, doors and engine food open.
9) With about 20 mm (0.8 in.) of dry bulb thermometer 

(1) put right in front of center ventilation louver and a 
wet and dry bulb thermometer (2) near air inlet (3) of 
HVAC unit.

10) Check for each pressure of low side and high side if it is within shaded range of graph. If each gauge reading is out 

of specified pressure, correct defective part referring to the table.

Low side and high side pressure example, gauges should read as follows when ambient temperature is 30 

°C (86 °F)
Pressure on high pressure gauge (HI): 1340 – 1670 kPa (13.4 – 16.7 kg/cm

2

, 191 – 237 psi)

Pressure on high pressure gauge (LO): 280 – 390 kPa (2.8 – 3.9 kg/cm

2

, 40 – 55 psi)

NOTE
Pressure registered on gauge varies with ambient temperature. Therefore, use the graphs when 
determining if pressures are normal or not.

 

1

3

2

I5JB0A720011-01

14.2

28.4

Pressure of Lo

Pressure Gauge

22

312.9

2200

0

1

2

3

30

70

30

70

%

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

21

298.7

2100

20

42.7

56.9

71.1

85.3

99.5

113.8

128.0

142.2

151.4

170.6

184.9

199.1

213.3

227.5

241.7

256.0

270.2

284.4

100

200

300

400

500

600

700

800

900

1000

1100

1200

1300

1400

1500

1600

1700

1800

1900

2000

25

30

35

77

86

95

psi

kPa     kg/cm

2

Ambient Temperature

 C
 F

w

Pressure of High Pressure

Gauge

“A”

“B”

“C”

“D”

Humidity

Acceptab

le 

range

Acceptab

le range

I6JB01720005-02

7B-22 Air Conditioning System: 

High pressure gauge

Low pressure gauge

Condition

Possible Cause

Correction

Pressure is higher than 
acceptable range
(“A” area)

Refrigerant overcharged

Recharge.

Expansion valve frozen or clogged

Check expansion valve.

Clogged refrigerant passage of high side

Clean or replace.

Radiator cooling fan malfunction (Insufficient 
cooling of condenser)

Check radiator cooling fan.

Dirty or bent condenser fins (Insufficient 
cooling of condenser)

Clean or repair.

Compressor malfunction (Insufficient oil etc.) Check compressor.
Engine overheat

Check engine cooling system referring to 
“Engine Cooling Symptom Diagnosis in 
Section 1F”.

Pressure is lower than 
acceptable range
(“B” area)

Insufficient refrigerant (Insufficient charge or 
leakage)

Check for leakage, repair if necessary and 
recharge.

Expansion valve malfunction (valve opens too 
wide)

Check expansion valve.

Compressor malfunction (Insufficient 
compression)

Check compressor.

Condition

Possible Cause

Correction

Pressure is higher than 
acceptable range 
(“C” area)

Expansion valve malfunction (valve opens too 
wide)

Check expansion valve.

Compressor malfunction (Insufficient 
compression)

Check compressor.

Pressure is lower than 
acceptable range 
(“D” area)

Insufficient refrigerant (Insufficient charge or 
leakage)

Check for leakage, repair if necessary and 
recharge.

Expansion valve malfunction (valve opens too 
narrow)

Check expansion valve.

Clogged refrigerant passage (crashed pipe)

Repair or replace.

Air Conditioning System:  7B-23

11) Check inlet port temperature-to-outlet port temperature relationship using graph.

For example, if A/C evaporator inlet port temperature is 30 

°C (86 °F) and center ventilation louver temperature is 

13 

°C (55.4 °F), their crossing point is within acceptable range as shown in the graph in this case, cooling 

performance is satisfactory and proper.

12) If crossing point is out of acceptable range, diagnose trouble referring to the following table.

Thermometer at center duct

NOTE
If ambient temperature is within 30 

°C (86 °F), it is possible to diagnose A/C system in detail referring 

to the following table.

 

T

e

mp

. at Air Outlet of Center 

V

e

ntilation Louv

er 

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

46.4

48.2

7

44.6

50.0

51.8

53.6

55.4

57.2

59.0

60.8

62.6

64.4

66.2

68.0

69.8

71.6

73.4

75.2

77.0

78.8

80.6

25

30

35

77

86

95

 F       C

 C
 F

“E”

“F”

Temp. near Air Inlet of HVAC unit

30

70

%

Humidit

y

Acceptable range

I6JB01720006-01

Condition

Possible Cause

Correction

Crossing point is higher 
than acceptable range
(“E” area)

Insufficient or excessive charge of refrigerant Check refrigerant pressure.
Dirty or bent A/C evaporator fins

Clean or repair.

Air leakage from cooling (heater) unit or air 
duct

Repair or replace.

Malfunctioning, switch over function of 
damper in cooling (heater) unit

Repair or replace.

Compressor malfunction

Check compressor.

Crossing point is lower 
than acceptable range
(“F” area)

Insufficient air volume from center duct 
(Heater blower malfunction)

Check blower motor and fan.

Compressor malfunction

Check compressor.