YH4
GRAND
VITARA
1B-8 AIR CONDITIONING (OPTIONAL)
DIAGNOSIS OF ABNORMAL NOISE
There are various types of noise, ranging from those produced in the engine compartment to those from the pas-
senger compartment, also from rumbling noises to whistling noises.
ABNORMAL NOISE FROM COMPRESSOR
ConditionPossible CauseCorrection
During compressor operation, a
rumbling noise is heard
proportional to engine
revolutions.Inadequate clearance in piston
area (piston or swash-plate).Repair or replace compressor as
necessary.
A loud noise is heard at a certain
rpm, disproportionately to engine
revolution.Loose or faulty V-belt.
Loose mounting bolts.Adjust V-belt tension, or
replace belt.
Retighten mounting bolts.
A loud rattle is heard at low
engine rpm.Loose compressor center bolt.Retighten center bolt.
Replace compressor if it was
operated in this condition for a
long time.
ABNORMAL NOISE FROM MAGNETIC CLUTCH
ConditionPossible CauseCorrection
A rumbling noise is heard when
compressor is not operating.Worn or damaged bearings.Replace bearings.
A chattering noise is heard when
compressor is engaged.Faulty clutch gap (excessive).
Worn clutch friction surface.
Compressor oil leaked from shaft
seal, contaminating the friction
surface.Adjust clutch gap.
Replace clutch.
Replace compressor shaft oil
seal.
ABNORMAL NOISE FROM TUBING
ConditionPossible CauseCorrection
A droning noise is heard inside
vehicle, but not particularly
noticeable in engine
compartment.Faulty tubing clamps.
Resonance caused by pulsation
from variations in refrigerant
pressure.Reposition clamps or increase
the number of clamps.
Attach a silencer to tubing, or
modify its position and length.
ABNORMAL NOISE FROM CONDENSER
ConditionPossible CauseCorrection
Considerable vibration in
condenser.Resonance from condenser
mounting stay and body.Firmly insert a silencer between
condenser mounting stay and
body.
YH4
GRAND
VITARA
AIR CONDITIONING (OPTIONAL) 1B-9
ABNORMAL NOISE FROM CRANKSHAFT PULLEY
ConditionPossible CauseCorrection
A large rattling noise is heard at
idle or sudden acceleration.Loosen pulley mounting bolt.
Worn or broken bearings.Retighten bolt.
Replace bearings.
ABNORMAL NOISE FROM TENSION PULLEY
ConditionPossible CauseCorrection
Clattering noise is heard from
pulley.
Pulley cranks upon contact.Worn or damaged bearings.
Cracked or loose bracket.Replace bearings.
Replace or retighten bracket.
ABNORMAL NOISE FROM EVAPORATOR
ConditionPossible CauseCorrection
Whistling sound is heard from
evaporator.Depending on the combination of
the interior / exterior
temperatures, engine rpm and
refrigerant pressure, the
refrigerant flowing out of the
expansion valve may, under
certain conditions, make a
whistling sound.At times, slightly decreasing
refrigerant volume may stop this
noise.
Inspect expansion valve and
replace if faulty.
ABNORMAL NOISE FROM BLOWER MOTOR
ConditionPossible CauseCorrection
Blower motor emits a chirping
sound in proportion to its speed of
rotation.
Fluttering noise or large droning
noise is heard from blower motor.Worn or damaged motor brushes
or commutator.
Leaves or other debris
introduced from fresh air inlet to
blower motor.Repair or replace blower motor.
Remove debris and make sure
that the screen at fresh air inlet is
intact.
YH4
GRAND
VITARA
AIR CONDITIONING (OPTIONAL) 1B-15
AMBIENT TEMPERATURE WITHIN 30 ± 35C (85 ± 95F)
CONDITION
MANIFOLD
GAUGEMPa
(kg/cm2)
(psi)DETAILCAUSECORRECTION
LoHi
0.23 ± 0.35
(2.3 ± 3.5)
(33 ± 50)1.4 ± 1.75
(14 ± 17.5)
(200 ± 249)
Normal condition.ÐÐÐÐ
Negative
pressure0.5 ± 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 receiver / dryer.
Evacuate the A / C
system and recharge
with fresh refrigerant.
Normal:
0.23 ± 0.35
(2.3 ± 3.5)
(33 ± 50)
Abnormal:
Negative
pressureNormal:
1.4 ± 1.75
(14 ± 17.5)
(200 ± 249)
Abnormal:
0.69 ± 0.98
(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 receiver / dryer.
Evacuate A / C system
and recharge with fresh
refrigerant.
0.05 ± 0.15
(0.5 ± 1.5)
(4.2 ± 21.3)
0.69 ± 0.98
(7 ± 10)
(100 ± 142)
Both low and high pressure
sides indicate low readings.
Continuous air bubbles are
visible through sight glass.
Output air is slightly cold.Insufficient refrigerant in
system. (Refrigerant
leaking)Using a gas leak
detector, check for leaks
and repair as necessary.
Recharge refrigerant to a
specified amount.
If the pressure reading is
almost 0 when the
manifold gauges are
attached, check for any
leaks, repair them, and
evacuate the system.
0.4 ± 0.6
(4 ± 6)
(56.9 ± 85.3)
Pressure on low pressure
side is high.
Pressure on high pressure
side is low.
Both pressure becoming
equal right after A / C is
turned OFF.Internal leak in compressor.Inspect compressor and
repair or replace as
necessary.
035 045
High pressure reading on
both low and high pressure
sides.
Air bubbles are not visible
even when engine rpm is
lowered.Overcharged A / C system.
Faulty condenser cooling
operation.
Faulty condenser fan
operation.Adjust refrigerant to
specified amount.
Clean condenser.
Inspect and repair
condenser fan.
0.35 ± 0.45(3.5 ± 4.5)
(50 ± 64)
1.96 ± 2.45
(20 ± 25)
(285 ± 355)
High pressure reading on
both low and high pressure
sides.
Low pressure side tubing is
not cold when touched.
Air bubbles are visible
through sight glass.Presence of air in A / C
system. (Improperly
evacuated)Replace receiver / dryer.
Inspect quantity of
compressor oil and
presence of
contaminants in oil.
Evacuate system and
recharge with fresh
refrigerant.
0.45 ± 0.55
(4.5 ± 5.5)
(64 ± 78)
High pressure reading on
both low and high pressure
sides.
Large amount of frost or
dew on the low pressure
side tubing.Faulty expansion valve.
Refrigerant flow is not
regulated properly.Replace expansion
valve.
YH4
GRAND
VITARA
Fig. A
Fig. B
Fig. C
C51-3-6 For G16
and J20 engines
C51-3-25 For
H25 engine
1B-18 AIR CONDITIONING (OPTIONAL)
INSPECTION OF A / C CONTROLLER AND ITS
CIRCUITS
CAUTION:
A / C controller and ECM cannot be checked by itself.
It is strictly prohibited to connect voltmeter or ohmmeter to
A / C controller and ECM with couplers disconnected from it.
A / C controller (1) and its circuits can be checked at A / C controller
wiring couplers by measuring voltage.
Voltage Check
1) Remove A / C controller (1) from vehicle (refer to ªA / C CON-
TROLLER REMOVALº in this section).
2) Remove ECM (2) from vehicle.
3) Connect A / C controller couplers to A / C controller and connect
ECM couplers to ECM.
4) Check each terminal voltage with couplers connected by refer-
ing to the A / C CONTROLLER VOLTAGE VALUES TABLE the
later.
YH4
GRAND
VITARA
AIR CONDITIONING (OPTIONAL) 1B-21
TerminalWireCircuitMeasurement
groundNormal valueCondition
AC2-1L/YSensor groundGround to body
(Fig. A)± 0.4 ± 0 voltEngine running
1.5 volts
(3150 )Evaporator thermistor temperature at
approx. 15C (59F) with engine
running
AC2-2W/B
Evaporator
thermistor
temperature
(evaporator temp.
sensor) input
Ground to engine
(Fig. B)
2.62 volts
(6.311 )
Evaporator thermistor temperature at
approx. 1C (34F) with engine
running
* If the temperature is less than
approx. 1C, in this case
compressor and condenser fan
should be stop (come back at more
than approx. 2.5C (less than
5840 , 2.5 V))
H25
engine
E61-27 /
G16 J20Gr/W
Signal output to
A / C controller
(A / C ON
Ground to engine
(Fig C)
10 ± 14 volts
Required A / C ON (terminal AC-A13)
at engine running with normal
condition (refer to ªINSPECTION OF
ECM AND ITS CIRCUITº in Section
6E)
G16, J20
engines
E61-8
(
permission
signal)(Fig. C)
0 ± 1 volt
Except the above-mentioned with
engine running
In this case compressor should be
stop
H25
engine
E61-28 /
Y/B
Signal input from
A / C controller
Ground to engine
0 ± 1.5 voltsRequire A / C ON
G16, J20
engines
E61-17Y/B(A / C ON request
signal)
g
(Fig. C)
10 ± 14 voltsTurn off the A / C
H25
engine
E61-5 /
G16, J20
engines
E61-22
Y/L
A / C condenser
cooling fan relay
outputGround to engine
(Fig. C)0 ± 1 volt
Blower fan motor switch and A / C or
defroster position switch (see
NOTE) ON with engine running at
evaporator thermistor temperature
input more than approx. 2.5C (less
than 2.5 V (5840 )), refrigerant
pressure switch ON and signal
input from ECM ON
Engine coolant temperature sensor
more than 113C (236F) with
engine running
10 ± 14 voltsExcept the above-mentioned with
engine running
NOTE:
Defroster position switch circuit is equipped with LH vehicle only.
YH4
GRAND
VITARA
J20 engine
H25 engine G16 engine
1. Generator belt
2. Compressor drive belt3. Compressor pulley
4. Crankshaft pulley
1B-22 AIR CONDITIONING (OPTIONAL)
DRIVE BELT
INSPECTION
For G16 and H25 engines
Refer to Section 3B1 for details.
For J20 engine
Refer to Section 6H for details.
YH4
GRAND
VITARA
1. Electric leak detector
AIR CONDITIONING (OPTIONAL) 1B-29
REMOVING MANIFOLD GAUGE SET
When A / C system has been charged with a specified amount of re-
frigerant, remove manifold gauge set as follows:
1) Close low pressure-side valve of manifold gauge set, (The high
pressure-side valve is closed continuously during the process
of charging.).
2) Close refrigerant container valve.
3) Stop engine.
4) Using shop rag, remove charging hoses from service valves.
This operation must be performed rapidly.
WARNING:
High pressure-side is naturally under high pressure.
So, care must be used to protect your eyes and skin.
5) Put caps on service valves.
LEAK-TESTING REFRIGERANT SYSTEM
Whenever a refrigerant leak is suspected in the system or any ser-
vice operation has been performed which may result in disturbing
lines or connections, it is advisable to test for leaks.
Common sense should be used in performing any refrigerant leak
test, since the need and extent of any such test will, in general, de-
pend upon the nature of a complaint and the type of a service per-
formed on the system.
LIQUID LEAK DETECTORS
There are a number of fittings and places throughout the air condi-
tioning system where a liquid leak detector solution may be used
to pinpoint refrigerant leaks.
By merely applying the solution to the area in question with a swab,
bubbles will form within seconds if there is a leak.
For confined areas, such as sections of the evaporator and con-
denser, an electronic (gas) leak detector is more practical for deter-
mining leaks.
WARNING:
To prevent explosions or fires, make sure that there are no
flammables in the vicinity.
When exposed to fire, the refrigerant turns into a poison-
ous gas (phosgene). Do not inhale this gas.
YH4
GRAND
VITARA
2. Bolt
For CAMI production vehicle
For IWATA production vehicle
AIR CONDITIONING (OPTIONAL) 1B-33
A / C CONDENSER ASSEMBLY
INSPECTION
Check
a) condenser fins for blockage
b) condenser fittings for leakage
c) condenser fins for damage
Clogged condenser fins should be washed with water, and should
be dried with compressed air.
CAUTION:
Be careful not to damage condenser fins. If condenser fin is
bent, straighten it by using a screwdriver or pair of pliers. If
any leakage is found from fitting or tube, repair or replace
condenser.
REMOVAL
1) Disconnect negative (±) cable at battery.
2) Recover refrigerant by using recovery and recycling equipment.
Be sure to follow the instruction manual for the equipment.
The amount of compressor oil removed must be measured and
the same amount added to the system.
3) Remove front bumper assembly and remove lower stay (1) if
equipped (Refer to Section 9 ªBODY SERVICEº).
4) Disconnect compressor discharge hose (1) from condenser in-
let fittings.
CAUTION:
As soon as above hose and pipe are disconnected, cap
opened fittings so that moisture and dust do not enter
condenser.