TOYOTA AVALON 2001 Service User Guide

AC0YE-02
I12953I12946
I12964
Auto A/C:
Ambient Temperature
Sensor
Pressure Switch
Compressor
Relay Block No. 8

No. 2 Cooling Fan Relay

No. 3 Cooling Fan RelayJunction Block No. 8

Heater Main Relay

Magnetic Clutch Relay
Condenser Fan
Condenser
Auto A/C:
Solar Sensor
A/C Control Assembly

Auto A/C:
A/C Amplifier

Manual A/C:
A/C Switch
Manual A/C:
Blower Speed Control Switch

Manual A/C:
Mode Control Switch
Auto A/C:
Room Temperature Sensor
A/C Unit

Heater Radiator

Evaporator

Expansion Valve

Evaporator Temp. Sensor

Auto A/C
Air Mix Servomotor

Air Outlet Servomotor
Blower Unit

Blower Motor

Manual A/C:
Blower Resistor

Auto A/C:
Blower Motor Linear Controller

Air inlet Servomotor
Manual A/C:
Multi Display (Built
into the A/C amplifier)
AC-14
- AIR CONDITIONINGAIR CONDITIONING SYSTEM
1936 Author
: Date
:
2001 AVALON (RM808U)
LOCATION

AC0YB-02
I12286
ight Glass
- AIR CONDITIONINGAIR CONDITIONING SYSTEM
AC-3
1925 Author
: Date
:
2001 AVALON (RM808U)
ON-VEHICLE INSPECTION
1. INSPECT REFRIGERANT VOLUME
Observe the sight glass on the liquid tube.
Test conditions:
Running engine at 1,500 rpm
Blower speed control switch at ºHIº position
A/C switch ON
Temperature control dial at ºCOOLº position
Fully open the doors
ItemSymptomAmount of refrigerantRemedy
1Bubbles present in sight glassInsufficient*
(1) Check for gas leakage with gas leak de-
tector and repair if necessary
(2) Add refrigerant until bubbles disappear
2No bubbles present in sight glassNone, sufficient or too muchRefer item 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 temperatures higher than usual can be considered normal if cooling
is sufficient.

I01386
AC-4
- AIR CONDITIONINGAIR CONDITIONING SYSTEM
1926 Author
: Date
:
2001 AVALON (RM808U)
2. INSPECT REFRIGERANT PRESSURE WITH MAN-
IFOLD GAUGE SET
This is a method in which the trouble is located by using a man-
ifold gauge set. Read the manifold gauge pressure when the
these conditions are established.
Test conditions:
Temperature at the air inlet with the switch set
at RECIRC is 30 - 35 °C (86 - 95 °F)
Engine running at 1500 rpm
Blower speed control switch at ºHIº position
Temperature control dial on ºCOOLº position
HINT:
It should be noted that the gauge indications may vary slightly
due to ambient temperature conditions.
(1) Normally functioning refrigeration system.
Gauge reading:
Low pressure side:
0.15 - 0.25 MPa (1.5 - 2.5 kgf/cm
2)
High pressure side:
1.37 - 1.57 MPa (14 - 16 kgf/cm
2)

I01387
Condition : Periodically cools and then fails to cool
I01388
Condition: Insufficient cooling
- AIR CONDITIONINGAIR CONDITIONING SYSTEM
AC-5
1927 Author
: Date
:
2001 AVALON (RM808U)
(2) Moisture present in refrigeration system.
Symptom seen in
refrigeration systemProbable causeDiagnosisRemedy
During operation, pressure on low
pressure side sometimes become
a vacuum and sometime normal
Moisture entered in refrigeration
system freezes at expansion valve
orifice and temporarily stops cycle,
by normal state is restored after a
time when the ice melts Drier oversaturated state
 Moisture in refrigeration system
freezes at expansion valve orifice
and blocks circulation of refriger-
ant(1) Replace condenser
(2) Remove moisture in cycle
through 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 at some place in re-
frigeration systemInsufficient refrigerant in sys-
tem
 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

I01389
Condition: Insufficient cooling
I01449
Condition: Does not cool (Cools from time to time in some cases) AC-6
- AIR CONDITIONINGAIR CONDITIONING SYSTEM
1928 Author
: Date
:
2001 AVALON (RM808U)
(4) Poor circulation of refrigerant
Symptom seen in
refrigeration systemProbable causeDiagnosisRemedy
 Pressure low in both low and
high pressure sides
 Frost on tube from receiver to
unit
Refrigerant flow obstructed by dirt
in receiverReceiver cloggedReplace condenser
(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 be-
fore and after condenser/ drier or
expansion 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 condenser
(4) Evacuate air and charge new
refrigerant to proper amount
(5) For gas leakage from expan-
sion valve, replace expansion
valve

I01390
Condition: Insufficient cooling
I01392
Condition: Insufficient cooling
NOTE : These gauge indica-
tions are shown when the
refrigeration system has
been opened and the refrig-
erant charged without vacu-
um purging.
- AIR CONDITIONINGAIR CONDITIONING SYSTEM
AC-7
1929 Author
: Date
:
2001 AVALON (RM808U)
(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-
eration system
 Insufficient cooling of condenser Excessive refrigerant in
cycle " refrigerant over charged
 Condenser cooling " condenser
fins clogged of condenser fan
faulty
(1) Clean condenser
(2) Check condenser fan motor
operation
(3) If (1) and (2) are in normal
state, check amount of refrigerant
Charge proper amount of refriger-
ant
(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
touch
 Bubbles seen in sight glass
Air entered 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

I01450
Condition: Insufficient cooling
I01393
Condition : Does not cool AC-8
- AIR CONDITIONINGAIR CONDITIONING SYSTEM
1930 Author
: Date
:
2001 AVALON (RM808U)
(8) Expansion valve improperly
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) Defective compression compressor
Symptom seen in
refrigeration systemProbable causeDiagnosisRemedy
 Pressure too high on low and
high pressure sides
 Pressure too low on high pres-
sure side
Internal leak in compressor
 Compression defective
 Valve leaking or broken sliding
parts
Repair or replace compressor

N14519
Drain Hose
- AIR CONDITIONINGAIR CONDITIONING SYSTEM
AC-9
1931 Author
: Date
:
2001 AVALON (RM808U)
3. INSPECT FOR LEAKAGE OF REFRIGERANT
(a) Perform in these conditions:
Stop engine.
Secure good ventilation (If the gas leak detector
may not react to volatile gases which are not refrig-
erant, 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 compressor is OFF: approx. 392 - 588 kPa
(4 - 6 kgf/ cm
2, 57 - 85 psi)
(b) Bring the gas leak detector close to the drain hose before
performing the test.
HINT:
After the blower motor has stopped, leave the cooling unit
for more than 15 minutes.
Expose the gas leak detector sensor under the drain
hose.
When bring 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 resistor from the cooling unit. Then insert the gas
leak detector sensor into the unit and perform 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.

AC-10
- AIR CONDITIONINGAIR CONDITIONING SYSTEM
1932 Author
: Date
:
2001 AVALON (RM808U)
4. INSPECT IDLE-UP SPEED
(a) Warm up engine.
(b) Inspect idle-up speed when the these conditions are es-
tablished.
Test conditions:
Idle speed set correctly.
Steering wheel straight ahead
Blower speed control switch at HI
A/C switch ON
Steering wheel straight ahead
Magnetic clutch conditionIdle speed
Magnetic clutch not engaged700 ±50 rpm
Magnetic clutch engaged700 ±50 rpm
If idle speed is not as specified, check the IAC valve and idle
control system (See page SF-43,DI-102 ).

AC2810
AC0Y9-02
AC2811
N11084
Wrong Okay
HI LO HILO
- AIR CONDITIONINGAIR CONDITIONING SYSTEM
AC-1
1923 Author
: Date
:
2001 AVALON (RM808U)
AIR CONDITIONING SYSTEM
PRECAUTION
1. DO NOT HANDLE REFRIGERANT IN AN ENCLOSED
AREA OR WEAR EYE PROTECTION
2. ALWAYS WEAR EYE PROTECTION
3. BE CAREFUL NOT TO GET LIQUID REFRIGERANT IN
YOUR EYES OR ON YOUR SKIN
If liquid refrigerant gets in your eyes or on your skin.
(a) Wash the area with lots of cool water.
CAUTION:
Do not rub your eyes or skin.
(b) Apply clean petroleum jelly to the skin.
(c) Go immediately to a physician or hospital for professional
treatment.
4. NEVER HEAT CONTAINER OR EXPOSE IT TO NAKED
FLAME
5. BE CAREFUL NOT TO DROP CONTAINER AND NOT
TO APPLY PHYSICAL SHOCKS TO IT
6. DO NOT OPERATE COMPRESSOR WITHOUT
ENOUGH REFRIGERANT IN REFRIGERATION SYS-
TEM
If there is not enough refrigerant in the refrigerant system oil lu-
brication will be insufficient and compressor burnout may occur,
so that care to avoid this, necessary care should be taken.
7. DO NOT OPEN PRESSURE MANIFOLD VALVE WHILE
COMPRESSOR IS OPERATE
If the high pressure valve is opened, refrigerant flows in the re-
verse direction and could cause the charging cylinder to rup-
ture, so open and close the only low pressure valve.
8. BE CAREFUL NOT TO OVERCHARGE SYSTEM WITH
REFRIGERANT
If refrigerant is overcharged, it causes problems such as insuffi-
cient cooling, poor fuel economy, engine overheating etc.