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Thermometer at center ventilation louver
Trouble Diagnosis for Abnormal PressureS6RW0D7214002
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) unitRepair 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/cm2) (psi)
Detail
Lo Hi
0.27 – 0.39
(2.7 – 3.9)
(38.8 – 56.0)1.13 – 1.56
(11.4 – 15.6)
(162.3 – 221.8)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:
0.27 – 0.39
(2.7 – 3.9)
(38.8 – 56.0)
↑ ↓
Abnormal:
Negative pressureNormal:
1.13 – 1.56
(11.4 – 15.6)
(162.3 – 221.8)
↑ ↓
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.
Downloaded from www.Manualslib.com manuals search engine Air Conditioning System: Automatic Type 7B-39
General Description
Auto A/C System DescriptionS6RW0D7221001
The automatic type air conditioning system (auto A/C) is provided with the function to automatically control the inside
air temperature, fan speed, air flow outlet direction and air intake position by HVAC control module in addition to
functions of the manual type air conditioning system (manual A/C). Once the inside air temperature is set using the
temperature selector, HVAC control module automatically controls the inside air temperature at the constant level at all
times based on the inside air temperature, outside air temperature, amount of sunlight and engine coolant
temperature detected respectively by the inside air temperature sensor, outside air temperature sensor, sunload
sensor and ECT sensor. For the electronic control system components location, refer to “Electronic Control System
Components Location”. For the A/C system components location, refer to “A/C System Major Components Location”.
Auto A/C Electronic Control Input / Output Table
Temperature selector
MODE (air flow) selector
Blower speed selector
Air intake selector
AUTO switch A/C switch
Outside air
temperature
sensor
A/C refrigerant pressure sensor
Compressor relay
Blower motor controller
Temperature control actuator
Air flow control actuator
Air intake control actuator
BCM
ECM
Data link connector
HVAC control module
CPU
ECT sensor
Sunload sensor
Inside air temperature sensor
Evaporator temperature sensor
Condenser cooling fan relay
Wheel
speed
sensor
*
*
*
Combination meterABS control module
I6RW0C722001-01
*: CAN communication
Downloaded from www.Manualslib.com manuals search engine Air Conditioning System: Automatic Type 7B-41
On-Board Diagnostic System DescriptionS6RW0D7221004
NOTE
The diagnostic information as diagnostic
trouble code (DTC) can be known by using
SUZUKI scan tool. For further details, refer to
“DTC Check”.
HVAC control module detects malfunctions, which may
occur in the following area.
• Inside air temperature sensor
• Evaporator temperature sensor
• Sunload sensor
• Temperature control actuator
• Air flow control actuator
• Temperature selector of HVAC control module
• Air flow selector of HVAC control module
• Blower speed selector of HVAC control module
• Back-up power supply circuit of HAVC control module
• Serial communication line between BCM and HVAC
control module• Received data from BCM as follows
– Outside air temperature sensor signal
– ECT sensor signal
– A/C refrigerant pressure sensor signal
– VSS signal
– Engine type signal
– Combination meter spec signal
– CAN communication circuit failure signal
When HVAC control module detects malfunction, the “A/
C” indicator light (1) flashes to warn and the diagnostic
trouble code (DTC) is stored in the memory of the
module. When diagnosing trouble, the DTC can be
checked according to “DTC Check”.
Schematic and Routing Diagram
A/C System Air Flow DiagramS6RW0D7222001
Refer to “A/C System Air Flow Diagram”.
1
I5RW0A722002-01