Suzuki Grand Vitara JB416 / JB420 / JB419. Manual — part 384

7B-27 Air Conditioning System:

High pressure gauge

[A]: M16 engine model
[B]: J20 engine model

[C]: F9Q engine model

[C]

14.2

28.4

Pressure of Lo

Pressure Gauge

22

312.9

2200

0

1

23

327.1

2300

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

Acceptable range

I6JB0A720008-01

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: For
Petrol Engine Model 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.

Air Conditioning System: 7B-28

Low pressure gauge

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

15

°C (59 °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.

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.

[A]

[B]

T

e

mp

. at Air Outlet of Center

V

entilation Louv

er

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

46.4

48.2

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

82.4

25

30

35

77

86

95

F C

C
F

“E”

“F”

Temp. near Air Inlet of HVAC unit

30

70

%

Humidity

Acceptable range

T

emp

. at Air Outlet of Center

V

entilation Louv

er

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

46.4

48.2

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

82.4

25

30

35

77

86

95

F C

C
F

“E”

“F”

Temp. near Air Inlet of HVAC unit

30

70

%

Humidity

Acceptable range

I5JB0A720013-03

7B-29 Air Conditioning System:

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.

[A]: M16 engine model
[B]: J20 engine model

[C]: F9Q engine model

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

[C]

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

I6JB0A720009-01

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.

Air Conditioning System: 7B-30

Condition

Possible Cause

Correction

Manifold Gauge

MPa

(kg/cm

2

)

(psi)

Detail

Lo

Hi

M16 engine model

0.23 – 0.33

(2.3 – 3.3)

(33 – 47)

J20 engine model

0.22 – 0.31

(2.2 – 3.1)

(31 – 44)

F9Q engine model

0.23 – 0.33

(2.3 – 3.3)

(33 – 47)

M16 engine model

0.96 – 1.16
(9.6 – 11.6)

(136 – 165)

J20 engine model

1.10 – 1.45

(11.0 – 14.5)

(156 – 206)

F9Q engine model

1.57 – 1.97

(15.7 – 19.7)

(223 – 280)

Normal condition

—

—

Negative pressure

0.5 – 0.6

(5 – 6)

(71.2 – 85.3)

The low pressure side
reads a negative pressure,
and the high pressure side
reads an extremely low
pressure.
Presence of frost around
tubing to and from receiver/
dryer and expansion valve.

Dust particles or water
droplets are either stuck
or frozen inside
expansion valve,
preventing the
refrigerant from flowing.

Clean expansion valve.
Replace it if it cannot be
cleaned.
Replace desiccant.
Evacuate the A/C
system and recharge
with fresh refrigerant.

Normal:

M16 engine model

0.23 – 0.33

(2.3 – 3.3)

(33 – 47)

J20 engine model

0.22 – 0.31

(2.2 – 3.1)

(31 – 44)

F9Q engine model

0.23 – 0.33

(2.3 – 3.3)

(33 – 47)

↑ ↓

Abnormal:

Negative pressure

Normal:

M16 engine model

0.96 – 1.16
(9.6 – 11.6)

(136 – 165)

J20 engine model

1.10 – 1.45

(11.0 – 14.5)

(156 – 206)

F9Q engine model

1.57 – 1.97

(15.7 – 19.7)

(223 – 280)

↑ ↓

Abnormal:

0.7 – 1.0

(7 – 10)

(100 – 142)

During A/C operation, the
low pressure side
sometimes indicates
negative pressure, and
sometimes normal
pressure. Also high
pressure side reading
fluctuates between the
abnormal and normal
pressure.

Expansion valve is
frozen due to moisture
in the system, and
temporarily shuts off the
refrigeration cycle.

Replace expansion
valve.
Replace desiccant.
Evacuate A/C system
and recharge with fresh
refrigerant.