Page 9 of 1897
N13790
Low Pressure
Service Valve
High Pressure
Service Valve
I12287
Properly
Charged
Insufficiently
Charged
- AIR CONDITIONINGAIR CONDITIONING SYSTEM
AC-13
1935 Author: Date:
2001 AVALON (RM808U)
3. CHARGE REFRIGERANT INTO REFRIGERANT SYS-
TEM
If there is no leak after refrigerant leak check, charge the proper
amount of refrigerant into refrigeration system.
CAUTION:
Never run the engine when charging the system
through the high pressure side.
Do not open the low pressure hand a valve when the
system is being charged with liquid refrigerant.
(a) Open the high pressure hand valve fully.
(b) Charge specified amount of refrigerant, then close the
high pressure hand valve.
HINT:
A fully charged system is indicated by the sight glass being free
of any bubbles.
(c) Charge partially refrigeration system with refrigerant.
(1) Set vehicle in these conditions:
Running engine at 1,500 rpm
Blower speed control set at ºHIº
Temperature control set at ºMAX. COOLº
Air inlet control set at ºRECIRCº
Fully open doors (Sliding roof: closed)
(2) Open the low pressure hand valve.
CAUTION:
Do not open the high pressure hand valve.
(d) Charge refrigerant until bubbles disappear and check the
pressure on the gauge through the sight glass.
(e) Replenishment to be 100 ± 50 g after bubbles disapper.
Page 12 of 1897
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.
Page 16 of 1897
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
Page 19 of 1897
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 ).
Page 51 of 1897
AC2G4-01
I12297
12
I12298
3 AC-42
- AIR CONDITIONINGCOMPRESSOR AND MAGNETIC CLUTCH
1964 Author: Date:
2001 AVALON (RM808U)
COMPRESSOR AND MAGNETIC
CLUTCH
ON-VEHICLE INSPECTION
1. INSPECT COMPRESSOR FOR METALLIC SOUND
Check there is abnormal metallic sound from the compressor
when the A/C switch is ON.
If abnormal metallic sound is heard, replace the compressor as-
sembly.
2. INSPECT REFRIGERANT PRESSURE
(See page AC-3)
3. INSPECT VISUALLY FOR LEAKAGE OF REFRIGER-
ANT
Using a gas leak detector, check for leakage of refrigerant.
If there is any leakage, replace the compressor assembly.
4. INSPECT COMPRESSOR LOCK SENSOR RESIS-
TANCE
(a) Disconnect the connector.
(b) Measure resistance between terminals 1 and 2.
Standard resistance: 65 - 125 W at 20 °C (68 °F)
If resistance is not as specified, replace the sensor.
5. CHECK FOR LEAKAGE OF GREASE FROM CLUTCH
BEARING
6. CHECK FOR SIGNS OF OIL ON PRESSURE PLATE OR
ROTOR
7. INSPECT MAGNETIC CLUTCH BEARING FOR NOISE
(a) Start engine.
(b) Check for abnormal noise from the compressor when the
A/C switch is OFF.
If abnormal noise is being emitted, replace the magnetic clutch.
8. INSPECT MAGNETIC CLUTCH OPERATION
(a) Disconnect the connector.
(b) Connect the positive (+) lead from the battery to terminal
4 and the negative (-) lead to the body ground.
(c) Check that the magnetic clutch energized.
If operation is not as specified, replace the magnetic clutch.
Page 62 of 1897
AC104-03
I12942
1 2
- AIR CONDITIONINGCONDENSER FAN
AC-71
1993 Author: Date:
2001 AVALON (RM808U)
CONDENSER FAN
ON-VEHICLE INSPECTION
1. INSPECT CONDENSER FAN OPERATION
Inspect the fan operation at these conditions, as shown in the
chart.
Test conditions:
Start engine
Blower speed control switch position ºHIº
Temperature control dial at ºCOOLº position
Set on manifold gauge set
A/C switch ON
ConditionFan operation (Fan speed)
Engine coolant temperature
88 °C (190 °F) or belowRotate (Low speed)
Engine coolant temperature
98 °C (208 °F) or aboveRotate (High speed)
Refrigerant pressure is less than
1,520 kPa (15.5 kgf/cm2, 220 psi)Rotate (Low speed)
Refrigerant pressure is 1,520 kPa
(15.5 kgf/cm2, 220 psi) or aboveRotate (High speed)
If operation is not as specified, proceed to the next inspection.
2. INSPECT CONDENSER FAN MOTOR OPERATION
(a) Disconnect the fan connector.
(b) Connect battery and ammeter.
(c) Check that the fan rotates smoothly, and then check the
reading on the ammeter.
Specified amperage: 9.2 - 11.0 A at 20 °C (68 °F)
If operation is not as specified, replace the fan motor.
If operation is as specified, check the pressure switch, cooling
fan relays and water temp. switch.
Page 64 of 1897
CH0086
Wrong Correct
AC0YF-03
I14032
Generator
Crankshaft PulleyCompressor
N01881
DENSOBorroughs
- AIR CONDITIONINGDRIVE BELT
AC-17
1939 Author: Date:
2001 AVALON (RM808U)
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
Using a belt tension gauge, check the drive belt tension.
Drive belt tension:
New belt: 165 ± 22 lbf
Used belt: 88 ± 22 lbf
HINT:
ºNew beltº refers to a belt which has been used less than
5 minutes on the running engine.
ºUsed beltº refer to a belt which has been on a running en-
gine for 5 minutes or more.
After installing the drive belt, check that it fits properly in
the ribbed grooves.
Page 81 of 1897
I12940
1
23 4
AC100-03
Z13470
Magnetic clutch control
Low pressure side
ON (Continuity)
196 kpa
(2.0 kgf/cm
2, 28 psi)
OFF (No Continuity)High pressure side
3,140 kpa
(32.0 kgf/cm2, 455 psi)
OFF (No Continuity)
Z13471
Cooling fan control
ON1,520 kpa
(15.5 kgf/cm
2, 220 psi)
(No Continuity) (Continuity)
OFF
1,226 kpa
(12.5 kgf/cm
2, 178 psi)
- AIR CONDITIONINGPRESSURE SWITCH
AC-65
1987 Author: Date:
2001 AVALON (RM808U)
PRESSURE SWITCH
ON-VEHICLE INSPECTION
1. SET ON MANIFOLD GAUGE SET (See page AC-20)
2. DISCONNECT CONNECTOR FROM PRESSURE
SWITCH
3. RUN ENGINE AT APPROX. 1,500 RPM
4. Magnetic clutch control:
INSPECT PRESSURE SWITCH OPERATION
(a) Connect the positive (+) lead from the ohmmeter to termi-
nal 4 and the negative (-) lead to terminal 1.
(b) Check continuity between terminals when refrigerant
pressure is changed, as shown in the illustration.
If operation is not as specified, replace the pressure switch.
5. Cooling fan control:
INSPECT PRESSURE SWITCH OPERATION
(a) Connect the positive (+) lead from the ohmmeter to termi-
nal 2 and the negative (-) lead to terminal 3.
(b) Check continuity between terminals when refrigerant
pressure is changed, as shown in the illustration.
If operation is not as specified, replace the pressure switch.
6. STOP ENGINE AND SET OFF MANIFOLD GAUGE SET
7. CONNECT CONNECTOR TO PRESSURE SWITCH
