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
3. Bubbles
1B-10 AIR CONDITIONING (OPTIONAL)
QUICKLY CHECKING OF REFRIGERANT
CHARGE (IF EQUIPPED WITH SIGHT GLASS)
CHARGE OF REFRIGERANT
The following procedure can be used for quickly checking whether
the A / C system has a proper charge of refrigerant or not.
Run engine at fast idle, and operate A / C at its max. cooling capacity
for a few minutes. Then, look at the sight glass (1) on receiver / dryer
(2) and compare what is observed with the symptoms listed in
ªCHECKING REFRIGERANT CHARGEº table given below.
CHECKING REFRIGERANT CHARGE
CONDITIONPOSSIBLE CAUSESCORRECTION
Bubbles observed in sight glassInsufficient charge of refrigerant in
systemCheck system for leaks with a leak
tester.
No bubbles observed in sight glassNo charge or proper or too much
charge of refrigerant in systemRefer to the following item.
No temperature difference
between compressor inlet and
outletEmpty or nearly empty systemRecovery, evacuate and charge
system and then check it for leaks
with a leak tester.
Noticeable temperature difference
between compressor inlet and
outletProper or too much charge of
refrigerant in systemRefer to the following item.
When A / C is turned OFF,
refrigerant in sight glass clears
immediately and remains clearToo much charge of refrigerant in
systemDischarge excess charge of
refrigerant to adjust it to a specified
charge.
When A / C is turned OFF,
refrigerant in sight glass once
produces bubbles and then clearsProper charge of refrigerant in
systemNo correction needed because
charge of refrigerant is normal.
YH4
GRAND
VITARA
For CAMI production vehicle
For IWATA production vehicle
1B-12 AIR CONDITIONING (OPTIONAL)
PERFORMANCE DIAGNOSIS
1) Confirm that vehicle and environmental conditions are as fol-
lows.
Vehicle is not exposed to direct sun.
Ambient temperature is within 15C ± 35C (59F ± 95F).
2) Make sure that high pressure valve (1) and low pressure valve
(2) of manifold gauge are firmly closed.
3) Connect high pressure charging hose (3) to high pressure ser-
vice valve (5) on vehicle, and connect low pressure charging
hose (4) to low pressure service valve (6) on vehicle.
4) Bleed the air in charging hoses (3), (4) by loosening their respec-
tive 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.
5) Warm up engine to normal operating temperature (engine cool-
ant temperature at 80 ± 90C (176 ± 194F)) and keep it at spe-
cified idle speed. (Radiator cooling fan should not be working
when checking pressure and temperature.)
6) Turn A / C switch ON, and set blower switch at ªHIº (4th position),
temperature control knob at ªCOOLº, air outlet control knob at
ªFACEº, fresh / circulation control knob at ªCIRCULATIONº.
(Confirm that A / C compressor and condenser fan are working.)
7) Keep all windows, doors and engine food open.
Ambient temperature
15 ± 35C (59F ± 95F)
Engine rpmKeep to 1,500 rpm.
Blower motor switchMax. (4th position)
Temperature controlMax. cool
Air outlet controlFace
Vehicle doorsAll open
Air inlet door positionRecirculation
8) With about 20 mm (0.8 in.) of dry bulb thermometer (1) inserted
into center duct air outlet and another one set near evaporator
air inlet, read temperature indicated on each thermometer.
YH4
GRAND
VITARA
1B-14 AIR CONDITIONING (OPTIONAL)
HIGH PRESSURE CAUGE LOW PRESSURE GAUGE THERMOMETER AT
CENTER DUCT
Insufficient
cooling of
condenser
PERFORMANCE DIAGNOSIS TABLE
TESTING RESULTSPOSSIBLE CAUSEREMEDY
Pressure high
(ªAº area of high side
graph)Refrigerant overcharged
Expansion valve frozen or clogged
Clogged refrigerant passage of high side
Condenser fan malfunction
Dirty or bent condenser fins
Compressor malfunction (Insufficient oil etc.)
Engine overheatRecharge
Check expansion valve
Clean or replace
Check condenser fan
Clean or repair
Check compressor
Check engine cooling
system
Pressure low
(ªBº area of high side
graph)Insufficient refrigerant (Insufficient charge or
leakage)
Expansion valve malfunction (Valve opens too
wide)
Compressor malfunction (Insufficient
compression)Check for leakage, repair if
necessary and recharge
Check expansion valve
Check compressor
Pressure high
(ªAº area of low side
graph)Expansion valve malfunction (Valve opens too
wide)
Compressor malfunction (Insufficient
compression)Check expansion valve
Check compressor
Pressure low
(ªBº area of low side
graph)Insufficient refrigerant (Insufficient charge or
leakage)
Expansion valve malfunction (Valve opens too
narrow)
Clogged refrigerant passage (Crashed pipe)Check for leakage, repair if
necessary and recharge
Check expansion valve
Repair or replace
Outlet air temperature
at center duct is high
(Crossing point is in
area ªAº)Insufficient or excessive charge of refrigerant
Dirty or bent evaporator fins
Air leakage from cooling (heater) unit or air
duct
Malfunctioning, switchover function of damper
in cooling (heater) unit
Compressor malfunctionCheck refrigerant
pressure
Clean or repair
Repair or replace
Repair or replace
Check compressor
Outlet air temperature
at center duct is low
(Crossing point is in
area ªBº)Insufficient air volume from center duct
(Heater blower malfunction)
Compressor malfunctionCheck blower motor and
fan
Check compressor
NOTE:
If ambient temperature is within 30 ± 35C (85 ± 95F), it is possible to do using next page table for more
detail diagnosis.
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
SYSTEM CIRCUIT
A. To heater fuse
B. To rear defogger fuse
C. To ignition / meter fuse
D. To A / C fuse
E. Only LH vehicle1. Blower motor relay
2. Blower motor
3. Blower motor switch
4. A / C switch
5. Deflloster position switch
6. Deflloster / foot position switch7. Dual pressure (refrigerant
pressure) switch
8. A / C thermistor (evaporator
temperature sensor)
9. Compressor relay
10. Compressor11. Condenser fan motor relay
12. Condenser fan motor
13. A / C controller
14. ECM
15. Compressor thermal switch
(only IWATA production vehicle)
TERMINAL ARRANGEMENT OF A / C CONTROLLER
TERMINAL ARRANGEMENT OF ECM FOR G16, J20 ENGINE
TERMINAL ARRANGEMENT OF ECM FOR H25 ENGINE
H25 engine
E61-27
G16, J20
engines
E61-8
H25 engine
E61-28
G16, J20
engines
E61-17
1919
19H25 engine
E61-5
G16, J20
engines
E61-22
AIR CONDITIONING (OPTIONAL) 1B-19