HEATER AND MANUAL AIR CONDITIONER – Troubleshooting55-4
TROUBLESHOOTING
TROUBLESHOOTING PROCEDURES
1. Check air ducts, control rods, etc. for improper connection.
2. Check that the electrical connectors of the relevant components are connected securely and the
fuse is not blown.
3. Perform the troubleshooting as follows; first understand the items to be inspected and the the procedures
comprehensively using Trouble Symptom/Failed Component Cross-Reference Table and then inspect
the appropriate items sequentially.
4. Be sure to perform each component check after disconnecting the relevant connector.
Trouble Symptom/Failed Component Cross-Reference Table
Items to be checked1.
When the igni-
tion switch is
“ON”, the A/C
does not oper-
ate.2.
When the A/C
is operating,
temperature
inside the pas-
senger
compartment
does not
decrease (cool
air is not
emitted).3.
Blower fan
motor does not
turn.4.
Blower fan
motor does not
stop turning.5.
When A/C is
operating,
radiator fan
and condenser
fan do not run.
Fuse111
Harness, connector2212
Amount of refrigerant31
A/C compressor relay4
A/C compressor magnet
clutch5
Dual pressure switch623
A/C switch7
Blower switch832
Blower relay4
Resistor53
Blower motor6
Air thermo-sensor93
Condenser fan relay44
Condenser fan motor55
Radiator fan relay (HI, LO)66
Radiator fan motor77
Refrigerant temperature
switch108
Auto compressor control
unit119
Engine-ECU12108
HEATER AND MANUAL AIR CONDITIONER – Troubleshooting55-5
No.Trouble symp-
tomProblem causeRemedyRefer-
ence
page
1When the igni-
tion switch is
“ON”, the A/C
does not oper
Refrigerant leak or overfilling of refriger-
antReplenish the refrigerant, repair the
leak or take out some of the
refrigerant55-6
does not oper-
ate.A/C compressor relay is defectiveReplace the A/C compressor relay55-14ate.
A/C compressor magnetic clutch is
defectiveReplace the A/C compressor magnet
clutch55-26
Dual pressure switch is defectiveReplace the dual pressure switch55-13
A/C switch is defectiveReplace the A/C switch55-17
Blower switch is defectiveReplace the blower switch55-17
Air thermo-sensor is defectiveReplace the air thermo-sensor55-22
Refrigerant temperature switch is defec-
tiveReplace the refrigerant temperature
switch55-25
Automatic compressor-ECU is defectiveReplace the automatic compressor-
ECU–
2When the A/C is
operating, tem-
perat re inside
Refrigerant leakReplenish the refrigerant and repair
the leak55-6
perature inside
the
passengerDual pressure switch is defectiveReplace the dual pressure switch55-13the passenger
compartment
doesn’tde-Air thermo-sensor is defectiveReplace the air thermo-sensor–doesnt de-
crease (cool air
is not emitted)
Condenser fan relay is defectiveReplace the condenser fan relay55-14
is not emitted).Condenser fan motor is defectiveReplace the condenser fan motor55-29
Radiator fan relay (HI, LO) is defectiveReplace the radiator fan relay (HI, LO)55-14
Radiator fan motor is defectiveReplace the radiator fan motor–
Refrigerant temperature switch is defec-
tiveReplace the refrigerant temperature
switch55-25
Automatic compressor-ECU is defectiveReplace the automatic compressor-
ECU–
3Blower fan mo-
tor doesn’t turn
Blower switch is defectiveReplace the blower switch55-17
tor doesn’t turn.Blower relay is defectiveReplace the blower relay55-13
Resistor is defectiveReplace the resistor55-21
Blower fan motor is defectiveReplace the blower fan motor55-21
4Blower fan mo-
tor doesn’t stop
t rning
Defective harness between the blower
fan motor and the blower switchRepair the harness–
turning.Blower switch is defectiveReplace the blower switch55-17
Resistor is defectiveReplace the resistor55-21
5When the A/C is
operating con
Condenser fan relay is defectiveReplace the condenser fan relay55-14
operating con-
denser fan orCondenser fan motor is defectiveReplace the condenser fan motor55-29denser an or
radiator fan
does not runRadiator fan relay (HI, LO) is defectiveReplace the radiator fan relay (HI, LO)55-14does not run.
Radiator fan motor is defectiveReplace the radiator fan motor–
Dual pressure switch is defectiveReplace the dual pressure switch55-13
Engine-ECU is defectiveReplace the engine-ECU–
HEATER AND MANUAL AIR CONDITIONER – On-vehicle Service55-8
12. Evacuate to a vacuum reading of 100 kPa or higher (takes
approx. 10 minutes).
Start evacuation
Approx. for 10 minutes up to
100 kPa
Stop evacuation
Refrigerant charging
(until saturated pressure is reached)
Wait for 5 minutes
Air-tight checkIf faulty
Refrigerant charging
Gas leak check*If faultyRetighten connections
*: If the leaking point cannot be located even after
performing a gas leak check, ask an expert for
checking the system.
13. Return the handle of the adapter valve 1 to the original
position (valve closed), turn off the vacuum pump adapter
switch and leave as it is for 5 minutes.
14. Carry out a leak test. (Good if the negative pressure
does not drop.)
15. With the handle turned back all the way (valve open),
install the charging valve to the service can.
16. Remove the adaptor valve 1 from the gauge manifold
and install the service can.
17. Tighten the handle of the charging valve (valve closed)
and puncture the service can.
18. Turn the handle of the charging valve back (valve open)
and tighten the handle of the adaptor valve 1 (valve open)
to charge the system with refrigerant.
19. If the refrigerant is not drawn in, turn the handle of the
adaptor valve 1 back all the way (valve closed).
20. Check for gas leaks using a leak detector.
Caution
The leak detector for R134a should be used.
21. Start the engine.
22. Operate the A/C and set to the lowest temperature (MAX.
COOL).
23. Fix the engine speed at 1,500 r/min.
24. Tighten the handle of the adaptor valve 1 (valve open)
to charge the required volume of refrigerant.
Caution
If the service can is inverted, liquid refrigerant may
be drawn into the compressor damaging it by liquid
compression. Keep the service can upright to ensure
that refrigerant is charged in gas state.
25. After charging with refrigerant, turn the handle of the
adaptor valve 1 back all the way (valve closed).
26. Tighten the charging valve handle (valve closed).
Charging
valveAdapter valve
(for low pressure)
Charging hose
(blue)
R134a
Service
can
Quick joint
(for low pressure)
Low-
pressure
service
valveHigh-
pressure
service
valve
Air conditioning system
HEATER AND MANUAL AIR CONDITIONER – On-vehicle Service55-9
27. Remove the quick joint 2 from the low-pressure service
valve.
28. Remove the service can.
NOTE
If the service can is not emptied completely, keep the
handles of the charging valve and adaptor valve 1 closed
for the next charging.
REFRIGERANT CHARGING AMOUNT CHECK
1. Start the engine.
2. Operate A/C and set the temperature control to MAX
COOL.
3. Fix the engine speed at 1,500 r/min.
4. Check the refrigerant level (bubble generation) through
the sight glass of the receiver.
ItemCondition
Proper levelBubbles are generated some times. No
bubbles appear when the engine speed is
slightly increased.
Level too lowA large amount of air bubbles are generated. If
it looks milky white, the level is excessively
lowered.
Level too highNo air bubbles appear.
5. If the level is too low, add the refrigerant, and if the level
is too high, drain the refrigerant as necessary.
Caution
Be sure to work at the low-pressure side service valve.
Proper level Level too low Level too high
Bubble Bubble
HEATER AND MANUAL AIR CONDITIONER – On-vehicle Service55-10
REPLENISHING SYSTEM
1. Connect the charging hose (blue) to the adapter valve
1 with the handle fully turned back (valve closed).
2. Connect the charging hose (blue) to the quick joint 2
and to the low pressure service valve.
Caution
Never connect to the high-pressure side since
otherwise the refrigerant could flow back.
3. Open and close the valve by operating the handle of
the adapter valve 1 to bleed air from inside the charging
hose.
4. With the handle turned back all the way (valve open),
install the charging valve to the service van.
5. Tighten the handle of the charging valve (valve closed)
and puncture the service can.
6. Install the charging valve to the adapter valve 1 and turn
back the handle all the way (valve open).
7. Start the engine.
8. Operate the A/C and set to the lowest temperature (MAX.
COOL).
9. Fix the engine speed at 1,500 r/min.
10. Tighten the handle of the adapter valve 1 (valve open).
Replenish the system with refrigerant while checking the
level through the sight glass.
After charging with refrigerant, turn the handles of the
charging valve and the adapter valve 1 all the way back
(valve closed), then remove the quick joint 2.
NOTE
If the service can is not emptied completely, keep the
handles of the charging valve and adaptor valve closed
for the next charging.Charging
valveAdapter valve
(for low pressure)
Charging hose
(blue)
R134a
Service
can
Quick joint
(for low pressure)
Low-
pressure
service
valveHigh-
pressure
service
valve
Air conditioning system
HEATER AND MANUAL AIR CONDITIONER – On-vehicle Service55-11
DISCHARGING SYSTEM
1. Run the engine at an engine speed of 1,200–1,500 r/min
for approximately 5 minutes with the A/C operating to
return to the oil.
NOTE
Returning the oil will be more effective if it is done while
driving.
2. Stop the engine.
3. Connect the charging hose (blue) to the adaptor valve
1 with its handle turned back all the way (valve closed).
4. Connect the quick joint 2 to the charging hose (blue),
and install the quick joint to the low-pressure service valve.
NOTE
The low-pressure service valve is provided on the suction
pipe.
Caution
(1) To connect the quick joint, press section “A” firmly
against the service valve until a click is heard.
(2) When connecting, run your hand along the hose
while pressing to ensure that there are no bends
in the hose.
5. Place the adaptor valve 1 inside the container and
discharge the refrigerant by opening the handle gradually
so that oil does not gush out.
NOTE
Any oil remaining in the container should be returned
to the A/C system.
PERFORMANCE TEST
1. The vehicle to be tested should be placed in a place
that is not exposed to direct sunlight.
2. The ambient condition should be 16 – 30 °C in temperature
and 60 – 100 % in relative humidity.
3. Open all the doors so that the air condition inside the
passenger compartment may be identical to that of the
outside.
4. With the high-pressure side of the gauge manifold closed,
connect the charging hose (red) to the gauge manifold
high-pressure side. Attach the quick joint for high-pressure
to the charging hose (red) and install it to the high-pressure
service valve on the vehicle side.
NOTE
The high-pressure service valve is found on liquid pipe
B.
Sleeve
Low-
pressure
service
valveHigh-
pressure
service
valve
Air conditioning system Adapter
valve (for low
pressure)Charging hose
(blue)
Quick joint (for
low pressure)Air conditioning
compressor oilA
Low-pressure
valve
Gauge manifold
Charging hose (red)
Quick joint
(for high pressure)
Low-
pressure
service
valve
Sleeve
Low-pressure
gaugeHigh-pressure
gauge
High-
pressure
service
valve
Air conditioning system
A
High-
pressure
valve
HEATER AND MANUAL AIR CONDITIONER – On-vehicle Service55-12
Caution
(1) To connect the quick joint, press section “A” firmly
against the service valve until a click is heard.
(2) When connecting, run your hand along the hose
while pressing to ensure that there are no bends
in the hose.
5. Start the engine.
6. Set the blower switch to HI (Fast) position
7. Set the A/C switch to ON position
8. Set the temperature control to Max. cooling position
9. Set the mode selection to Face position
10. Set the air selection to Recirculation position
11. Fix engine speed to 1,500 r/min.
12. Check that the high-pressure side pressure is 1,667 –
1,765 kPa.
NOTE
If the pressure is not within this range, adjust it as follows;
cool down the condenser using a cooling fan if the
pressure is higher, and cover the condenser to protect
it from ventilation air if it is lower.
13. Set a dry-bulb/wet-bulb thermometer at the air inlet, and
set a dry-bulb thermometer at the air outlet.
Caution
(1) Set the dry-bulb thermometer at a position where
the temperature sensing section can be directly
blown with cooled air.
(2) Place the dry-bulb/wet-bulb thermometer at a
position where it is not exposed to cooled air
blown out.
14. After the temperature of the air blown out from the air
outlet has been stabilized (10 – 15 minutes after starting),
read the dry-bulb thermometer set at the air outlet and
the wet-valve thermometer set at the air inlet.
15. The air conditioning system is considered in good
condition if the intersecting point of the measurements
obtained in Step (14) is below the performance evaluation
reference line on the graph.
Caution
Do not remove the quick joint immediately after the
performance test has been completed. Stop the engine
and wait until the high-pressure side pressure of the
gauge manifold has been lowered sufficiently.
Dry-bulb ther-
mometer
Dry-bulb/wet-bulb
thermometer
Reading of wet-bulb thermometer
set at air inlet (°C)
Performance
evaluation
reference line
In order
Not in order
0Reading of dry-bulb
thermometer set at air outlet
(°C)
15 20 25 30 5 10 15 20 25
– Heater Unit and Blower Unit HEATER AND MANUAL
AIR CONDITIONER55-18
HEATER UNIT AND BLOWER UNIT
REMOVAL AND INSTALLATION
Pre-removal and Post-installation Operation
Engine Coolant Draining and Refilling
Air Cleaner Cover and Hose Removal and
Installation
Floor Console and Instrument Panel Removal and
Installation
Rear Seat Heater Duct Removal and Installation
1
34
5
6
2 7 8
9 1011
Removal steps
1. Center reinforcement RH
2. Heater control assembly
3. Center reinforcement LH
4. Center ventilation duct
5. Foot distribution duct
6. Joint duct7. Blower unit
8. Heater hose
9. Heater unit
10. Heater core support
11. Heater core