Page 3737 of 4323
AC±2
± AIR CONDITIONINGAIR CONDITIONING SYSTEM
3729 Author: Date:
2005 SEQUOIA (RM1146U)
9. SUPPLEMENTAL RESTRAINT SYSTEM (SRS)
The SEQUOIA is equipped with an SRS (Supplemental Re-
straint System) such as the driver, passenger, side, and curtain
shield airbags. Failure to carry out service operation in the cor-
rect sequence could cause the SRS to unexpectedly deploy
during servicing, possibly leading to a serious accident. Before
servicing (including removal or installation of parts, inspection
or replacement), be sure to read the precautionary notices in
the RS section.
Page 3738 of 4323

I21357
Sight Glass
AC1JT±06
± AIR CONDITIONINGAIR CONDITIONING SYSTEM
AC±3
3730 Author: Date:
2005 SEQUOIA (RM1146U)
ON±VEHICLE INSPECTION
1. INSPECT REFRIGERANT VOLUME
Observe the sight glass on the liquid tube.
Test conditions:
Running engine at 1,500 rpm
Single A/C:
Front blower speed control dial at ºHIº position
Dual A/C:
Front and rear blower speed set at ºHIº position
A/C switch ON
Single A/C:
Front temperature control dial at ºMAX. COOLº position
Dual A/C:
Front temperature control dial at ºMAX. COOLº position
Rear temperature control set at 18.5°C (65°F)
Fully open the doors
ItemSymptomAmount of refrigerantRemedy
1Bubbles are present in sight glass continu-
ouslyInsufficient*
(1) Check for gas leakage with gas leak de-
tector and repair if necessary
(2) Add refrigerant until bubbles disappear
2No bubbles are present in sight glassNone, sufficient or too muchRefer to items 3 and 4
3No temperature difference between com-
pressor inlet and outletEmpty or nearly empty
(1) Check for gas leakage with gas leak de-
tector and repair if necessary
(2) Add refrigerant until bubbles disappear
4Temperature between compressor inlet and
outlet is noticeably differentCorrect or too muchRefer to items 5 and 6
5Immediately after air conditioning is turned
off, refrigerant in sight glass stays clearToo much
(1) Discharge refrigerant
(2) Evacuate air and charge proper amount
of purified refrigerant
6When air conditioning is turned off, refriger-
ant foams and then stays clearCorrect±
*: Bubbles in the sight glass with ambient temperature higher than usual can be considered normal if cooling
is sufficient.
Page 3739 of 4323
I21803
Single A/C:
Dual A/C: AC±4
± AIR CONDITIONINGAIR CONDITIONING SYSTEM
3731 Author: Date:
2005 SEQUOIA (RM1146U)
2. INSPECT REFRIGERANT PRESSURE WITH MAN-
IFOLD GAUGE SET
This is a method for checking the A/C system by using a man-
ifold gauge set. Read the manifold gauge pressure when the
conditions below are met.
Test conditions:
Temperature at the air inlet with R/F switch set at RECIRC
is 30 to 35°C (86 to 95°F)
Engine running at 1500 rpm
Blower speed control switch at ºHIº position
Temperature control dial at ºMAX. COOLº position
Dual A/C:
Rear temperature control set at 18.5°C (65°F)
HINT:
Gauge indications may vary slightly due to ambient tempera-
ture conditions.
(1) Normally functioning refrigeration system.
Gauge reading:
Single A/C:
GaugeMPakgf´cm2
Low pressure0.15 to 0.251.5 to 2.5
High pressure1.6 to 1.816 to 18
Dual A/C:
GaugeMPakgf´cm2
Low pressure0.25 to 0.352.5 to 3.5
High pressure1.9 to 2.119 to 21
Page 3740 of 4323

I21804
Condition: Periodically cools and then fails to cool
Single A/C:
Dual A/C:
I22613
Condition: Insufficient cooling
Single A/C:
Dual A/C:
± AIR CONDITIONINGAIR CONDITIONING SYSTEM
AC±5
3732 Author: Date:
2005 SEQUOIA (RM1146U)
(2) Moisture present in refrigeration system.
Symptom seen in
refrigeration systemProbable causeDiagnosisRemedy
During operation, pressure on low
pressure side cycles between vac-
uum and normal
Moisture in refrigeration system
freezes at expansion valve orifice
and temporarily stops cycle, but
normal state is restored after the
ice melts Drier in oversaturated state
Moisture in refrigeration system
freezes at expansion valve orifice
and blocks circulation of refriger-
ant(1) Replace receiver
(2) Remove moisture in cycle by
repeatedly evacuating air
(3) Charge proper amount of new
refrigerant
(3) Insufficient cooling
Symptom seen in
refrigeration systemProbable causeDiagnosisRemedy
Pressure low on both low and
high pressure sides
Bubbles seen in sight glass con-
tinuously
Insufficient cooling performance
Gas leakage in refrigeration sys-
tem Insufficient refrigerant in system
Refrigerant leaking
(1) Check for gas leakage with gas
leak detector and repair if neces-
sary
(2) Charge proper amount of re-
frigerant
(3) If indicated pressure value is
near 0 when connected to gauge,
create the vacuum after inspecting
and repairing the location of the
leak
Page 3741 of 4323

I01389
Condition: Insufficient cooling
I01449
Condition: Does not cool (Cools from time to time in some cases) AC±6
± AIR CONDITIONINGAIR CONDITIONING SYSTEM
3733 Author: Date:
2005 SEQUOIA (RM1146U)
(4) Poor circulation of refrigerant
Symptom seen in
refrigeration systemProbable causeDiagnosisRemedy
Pressure low on both low and
high pressure sides
Frost on tube from receiver to
unit
Refrigerant flow obstructed by dirt
in receiverReceiver cloggedReplace receiver
(5) Refrigerant does not circulate
Symptom seen in
refrigeration systemProbable causeDiagnosisRemedy
Vacuum indicated on low pres-
sure side, very low pressure indi-
cated on high pressure side
Frost or dew seen on piping on
both sides of receiver/ drier or ex-
pansion valve Refrigerant flow obstructed by
moisture or dirt in refrigeration sys-
tem
Refrigerant flow obstructed by
gas leakage from expansion valve
Refrigerant does not circulate
(1) Check expansion valve
(2) Clean out dirt in expansion
valve by blowing with air
(3) Replace receiver
(4) Evacuate air and charge new
refrigerant to proper amount
(5) For gas leakage from expan-
sion valve, replace expansion
valve
Page 3742 of 4323

I22614
Condition: Insufficient cooling
Single A/C:
Dual A/C:
I22614
Condition: Insufficient cooling
Single A/C:
Dual A/C:
NOTE: These indications
are shown when the refrig-
eration system has been
opened and the refrigerant
has been charged without
vacuum purging.
± AIR CONDITIONINGAIR CONDITIONING SYSTEM
AC±7
3734 Author: Date:
2005 SEQUOIA (RM1146U)
(6) Refrigerant overcharged or insufficient cooling of
condenser
Symptom seen in
refrigeration systemProbable causeDiagnosisRemedy
Pressure too high on both low
and high pressure sides
No air bubbles seen through the
sight glass even when the engine
rpm is lowered Unable to develop sufficient per-
formance due to excessive refrig-
erant
Insufficient cooling of condenser Excessive refrigerant in
cycle"refrigerant overcharged
Condenser cooling
insufficient"condenser fins
clogged or cooling fan faulty
(1) Clean condenser
(2) Check cooling fan with fluid
coupling operation
(3) If (1) and (2) are in normal
state, check amount of refrigerant
and charge proper amount of re-
frigerant
(7) Air present in refrigeration system
Symptom seen in
refrigeration systemProbable causeDiagnosisRemedy
Pressure too high on both low
and high pressure sides
The low pressure piping hot to
the touch
Bubbles seen in sight glass
Air in refrigeration system
Air present in refrigeration sys-
tem
Insufficient vacuum purging
(1) Check compressor oil to see if
it is dirty or insufficient
(2) Evacuate air and charge new
refrigerant
Page 3743 of 4323
I22614
Condition: Insufficient cooling
Single A/C:
Dual A/C:
I22615
Condition: Does not cool
Single A/C:
Dual A/C: AC±8
± AIR CONDITIONINGAIR CONDITIONING SYSTEM
3735 Author: Date:
2005 SEQUOIA (RM1146U)
(8) Expansion valve malfunction
Symptom seen in
refrigeration systemProbable causeDiagnosisRemedy
Pressure too high on both low
and high pressure sides
Frost or large amount of dew on
piping on low pressure side
Trouble in expansion valve
Excessive refrigerant in low
pressure piping
Expansion valve opened too
wide
Check expansion valve
Replace if defective
(9) Insufficient compressor compression
Symptom seen in
refrigeration systemProbable causeDiagnosisRemedy
Pressure too high on both low
and high pressure sides
Pressure too low on high pres-
sure side
Internal leak in compressor
Low compression
Leak from valve or broken sliding
parts
Repair or replace compressor
Page 3744 of 4323

± AIR CONDITIONINGAIR CONDITIONING SYSTEM
AC±9
3736 Author: Date:
2005 SEQUOIA (RM1146U)
3. INSPECT IDLE±UP SPEED
(a) Warm up the engine.
(b) Inspect idle±up speed when the following conditions are
established.
Warm up engine
Blower speed control switch at ºHIº position
A/C switch ON
Temperature control dial at ºCOOLº position
Magnetic clutch conditionIdle±up speed
Magnetic clutch not engaged700 ± 50 rpm
Magnetic clutch engaged780 ± 50 rpm
If idle speed is not as specified, check the Idle control system.
4. INSPECT FOR LEAKAGE OF REFRIGERANT
(a) Perform under the following conditions:
Stop the engine.
Secure good ventilation (If not, the gas leak detec-
tor may react to volatile gases witch are not refriger-
ant, such as evaporated gasoline and exhaust gas.)
Repeat the test 2 or 3 times.
Make sure that there is some refrigerant remaining
in the refrigeration system.
When the compressor is OFF: approx. 392 to 588
kPa (4 to 6 kgf/ cm
2, 57 to 85 psi)
(b) Bring the gas leak detector close to the drain hose before
performing the test.
HINT:
After the blower motor stopped, leave the cooling unit for
more than 15 minutes.
Bring the gas leak detector sensor under the drain hose.
When bringing the gas leak detector close to the drain
hose, make sure that the gas leak detector does not react
to the volatile gases.
If such reaction is unavoidable, the vehicle must be lifted up.
(c) If gas leak is not detected on the drain hose, remove the
blower motor linear controller from the cooling unit. Then
insert the gas leak detector sensor into the unit and per-
form the test.
(d) Disconnect the connector and leave the pressure switch
for approx. 20 minutes. Then bring the gas leak detector
close to the pressure switch and perform the test.
(e) Bring the gas leak detector close to the refrigerant lines
and perform the test.