Page 6 of 1897
I12987
AC2GL-01
- AIR CONDITIONINGAIR CONDITIONING AMPLIFIER (Manual A/C)
AC-77
1999 Author: Date:
2001 AVALON (RM808U)
AIR CONDITIONING AMPLIFIER
(Manual A/C)
ON-VEHICLE INSPECTION
INSPECT A/C AMPLIFIER CIRCUIT
(a) Remove the multi display with connectors still connected.
(b) Inspect wire harness side connector from the back side,
as shown in the chart below.
Test conditions:
Running engine at idle speed
A/C switch ON
Temperature control dial ºMAX COOLº position
Blower speed control switch at ºHIº position
Set on manifold gauge set
Tester connectionConditionSpecified condition
Refrigerant pressure at 196 - 3,140 kPaBelow 1.0 V
1 - GroundRefrigerant pressure less than 196 kPa or more
than 3,140 kPaBattery positive voltage
2 - GroundConstantPulse generation
5 - GroundA/C switch ONBattery positive voltage
7 - GroundEvaporator temperature at 25 °C (77 °F)Approx. 1.5 kW
8G dA/C switch ONBattery positive voltage8 - GroundA/C switch OFFBelow 1.0 V
9G dA/C switch ONBelow 2.0 V9 - GroundA/C switch OFFNo voltage
10 G dConstantBattery positive voltage10 - GroundEngine speed at idle-up speedBelow 1.0 V
11 G dA/C switch OFFBattery positive voltage11 - GroundA/C switch ONBelow 0.7 V
11 G dMagnetic clutch is engagedBelow 1.0 V11 - GroundMagnetic clutch is not engagedBattery positive voltage
If the circuit is not as specified, inspect the circuits connected
to other parts.
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 13 of 1897
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)
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 18 of 1897
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.
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 20 of 1897
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.
