TOYOTA SEQUOIA 2001 Service Repair Manual

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

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

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

± 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.

AC1JU±07
N13795
Quick Disconnect
Adapter
Charging
Service ValveHose
N13794
Vacuum Pump
Vacuum Pump Adapter
N13791
Low Pressure
Service Valve
Vacuum Pump Adapter High Pressure
Service ValveManifold
Gauge
Set
AC±10
± AIR CONDITIONINGAIR CONDITIONING SYSTEM
3737 Author: Date:
2005 SEQUOIA (RM1146U)
EVACUATING
1. CONNECT QUICK DISCONNECT ADAPTER TO
CHARGING HOSES
2. REMOVE CAPS FROM SERVICE VALVES ON RE-
FRIGERANT LINES
3. SET MANIFOLD GAUGE SET
(a) Close both valves of the manifold gauge set.
(b) Connect the quick disconnect adapters to the service
valves.
4. EVACUATE AIR FROM REFRIGERATION SYSTEM
(a) Connect the vacuum pump adapter to the vacuum pump.
(b) Connect the center hose of the manifold gauge set to the
vacuum pump adapter.
(c) Open both the high and low side valves and run the vacu-
um pump.
(d) After 10 minutes or more, check that the low pressure
gauge indicates 750 mmHg (30 in. Hg) or more.
HINT:
If the reading is 750 mmHg (30 in. Hg) or more, close both
valves of the manifold gauge set and stop the vacuum pump.
Check the system for leaks and repair if necessary.
(e) Close both the high and low side valves and stop the vac-
uum pump.
(f) Leave the system in this condition for 5 minutes or more
and check that there is no change in gauge indication.

AC1JV±05
N13793
Charging Cylinder High Pressure
Service Valve Low Pressure
Service ValvePush
Air
N13792
Gas Leak
Detector
± AIR CONDITIONINGAIR CONDITIONING SYSTEM
AC±11
3738 Author: Date:
2005 SEQUOIA (RM1146U)
CHARGING
1. INSTALL CHARGING CYLINDER
HINT:
When handling the charging cylinder, always follow the direc-
tions given in the instruction manual.
(a) Charge the proper amount of refrigerant into the charging
cylinder.
(b) Connect the center hose to the charging cylinder.
CAUTION:
Do not open either the high or low side valve of the manifold
gauge set.
(c) Open the valve of the charging cylinder.
(d) Press the valve core on the side of the manifold gauge
and expel the air from the center hose.
2. INSPECT REFRIGERATION SYSTEM FOR LEAKS
(a) Open the high pressure side valve and charge refrigerant.
(b) When the low pressure gauge indicates 98 kPa
(1 kgf/cm
2, 14 psi), close the high pressure side valve.
(c) Using a gas leak detector, check the system for leakage.
CAUTION:
Use a refrigerant recovery/recycling machine to recover
the refrigerant whenever replacing parts.

N13790
Low Pressure
Service Valve
High Pressure
Service Valve
I21358
Properly
Charged
Insufficiently
Charged AC±12
± AIR CONDITIONINGAIR CONDITIONING SYSTEM
3739 Author: Date:
2005 SEQUOIA (RM1146U)
3. CHARGE REFRIGERANT INTO REFRIGERANT SYS-
TEM
If there is no leak after refrigerant leak check, charge the proper
amount of refrigerant into the refrigeration system.
CAUTION:

Never run the engine when charging the system
through the high pressure side.

Do not open the low pressure side valve when the
system is being charged with liquid refrigerant.
(a) Open the high pressure side valve fully.
(b) Charge specified amount of refrigerant, then close the
high pressure side valve.
HINT:
The system is fully charged if bubbles cannot be seen through
the sight glass.
(c) Partially charge the refrigeration system with refrigerant.
(1) Prepare the vehicle:

Running engine at 1,500 rpm

Single A/C:
Front blower speed control dial at ºHIº posi-
tion

Dual A/C:
Front and rear blower speed set at ºHIº posi-
tion

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)

Air inlet control set at ºRECIRCº

Fully open doors (Sliding roof: closed)
(2) Open the low pressure side valve.
CAUTION:
Do not open the high pressure side valve.
(d) Charge refrigerant until bubbles disappear and check the
pressure on the gauge through the sight glass.

AC1JW±06
I21418
R/B No. 2

Heater Main Relay
(Marking: HTR)
Compressor
Condenser
Receiver Pressure Switch
Integration Panel Assembly

A/C ECU

A/C Switch

Air Inlet Selector
Heater Unit

Heater Radiator

Air Mix Servomotor

Air Outlet Servomotor
Cooling Unit

Blower Motor Linear
Controller

Evaporator

Expansion Valve

ThermistorBlower Unit

Blower Motor

Air Inlet Servomotor
Water Valve
Rear Heater
Control Assembly
Condenser Fan
Ambient
Temperature
Sensor
Solar Sensor
Room
Temperature
Sensor
Rear Room Temperature Sensor
± AIR CONDITIONINGAIR CONDITIONING SYSTEM
AC±13
3740 Author: Date:
2005 SEQUOIA (RM1146U)
LOCATION

I21419
Water Valve
Air Outlet
Servomotor
Heater Radiator
Thermistor
Evaporator
Expansion Valve Power Transistor Blower Motor
AC±14
± AIR CONDITIONINGAIR CONDITIONING SYSTEM
3741 Author: Date:
2005 SEQUOIA (RM1146U)

CH0086
Correct Wrong
AC1JX±05
B00808
A
B
± AIR CONDITIONINGDRIVE BELT
AC±15
3742 Author: Date:
2005 SEQUOIA (RM1146U)
DRIVE BELT
ON±VEHICLE INSPECTION
1. INSPECT DRIVE BELT'S INSTALLATION CONDITION
Check that the drive belt fits properly in the ribbed grooves.
2. INSPECT DRIVE BELT TENSION
Check that the tension is within the A range on the auto tension-
er scale.
If the tension is not within the A range on the scale, replace the
belt with a new one.
HINT:
When replacing the drive belt with a new one, the belt's tension
should be within the B range on the belt tensioner scale.