2001 TOYOTA PRIUS air condition

I01387
Condition : Periodically cools and then fails to cool
I01388
Condition: Insufficient cooling
± AIR CONDITIONINGAIR CONDITIONING SYSTEM
AC±5
2001 PRIUS (RM778U)
(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
2001 PRIUS (RM778U)
(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
2001 PRIUS (RM778U)
(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
2001 PRIUS (RM778U)
(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
2001 PRIUS (RM778U)
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
2001 PRIUS (RM778U)
4. INSPECT IDLE±UP SPEED
(a) Activate inspection mode (See page IN±10).
(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 dial at HI
A/C switch ON
Magnetic clutch conditionIdle speed
Magnetic clutch not engaged1,000 ±50 rpm
Magnetic clutch engaged1,000 ±50 rpm
If idle speed is not as specified, check the engine ECU and
throttle body.

AC20C±03
N13793
Charging Cylinder High Pressure
Service Valve Low Pressure
Service ValvePush
Air
N13792
Gas Leak
Detector AC±12
± AIR CONDITIONINGAIR CONDITIONING SYSTEM
2001 PRIUS (RM778U)
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 both high and low hand valves of manifold
gauge set.
(c) Open the valve of charging cylinder.
(d) Press the valve core on the side of manifold gauge and
expel the air inside of the center hose.
2. INSPECT REFRIGERATION SYSTEM FOR LEAKS
(a) Open the high pressure hand valve and charge refriger-
ant.
(b) When the low pressure gauge indicates 98 kPa
(1 kgf/cm
2, 14 psi) close the high pressure hand valve.
(c) Using a gas leak detector, check the system for leakage.
If leak is found, repair the faulty component or connection.
CAUTION:
Use the refrigerant recovery/ recycling machine to recover
the refrigerant whenever replacing parts.

N13790
Low Pressure
Service Valve
High Pressure
Service Valve
I17972
Properly
Charged
Insufficiently
Charged
± AIR CONDITIONINGAIR CONDITIONING SYSTEM
AC±13
2001 PRIUS (RM778U)
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:

MAX. switch ON

Blower speed control set at ºHIº

Temperature control set at ºMAX. COOLº

Air inlet control set at ºRECIRCº

Running engine at 1,500 rpm

Fully open doors
(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.