Suzuki 2006 SX4, Service Manual

Page: 876 / 1478

7B-11 Air Conditioning System: Manual Type
Thermometer at center ventilation louver
Trouble Diagnosis for Abnormal Pressure
S6RW0C7214002
NOTE
Normal pressure values on high side and low side in following table are measured when the ambient
temperature is 30
°
C. As normal pressure values on high side and low side vary depending on the
ambient temperature, be sure to perform following steps first when diagnosing troubles.
1. Measure the ambient temperature and using that value, read the normal value from the graph given
in Step 10 of “A/C System Performance Inspection”.
2. Put that value in place of the normal pressure in following table.
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 door 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.
Condition
Possible cause Correction Manifold gauge MPa (kgf/cm 2 ) (psi)
Detail
Lo Hi
0.25 – 0.36
(2.5 – 3.6)
(35.6 – 51.2) 1.24 – 1.62
(12.4 – 16.2)
(176.3 – 230.4) 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. Replace expansion
valve.
Replace desiccant and
cap with filter.
Evacuate the A/C
system and recharge
with fresh refrigerant.
Normal:
0.25 – 0.36
(2.5 – 3.6)
(35.6 – 51.2)
↑ ↓
Abnormal:
Negative pressure
Normal:
1.24 – 1.62
(12.4 – 16.2)
(176.3 – 230.4)
↑ ↓
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 and
cap with filter.
Evacuate A/C system
and recharge with
fresh refrigerant.