ATC-26
AIR CONDITIONER CONTROL
AIR CONDITIONER CONTROL
PFP:27500
DescriptionEJS006B0
The front air control provides automatic regulation of the vehicle's interior temperature. The system is based
on the driver's and passenger's selected “set temperature”, regardless of the outside temperature changes.
This is done by utilizing a microcomputer, also referred to as the front air control, which receives input signals
from the following six sensors:
lAmbient sensor
lIn-vehicle sensor
lIntake sensor
lOptical sensor (one sensor for driver and passenger side)
lPBR (Position Balanced Resistor).
lVehicle speed sensor
The front air control uses these signals (including the set temperature) to automatically control:
lOutlet air volume
lAir temperature
lAir distribution
The front air control is used to select:
lOutlet air volume
lAir temperature/distribution
OperationEJS006B1
AIR MIX DOORS CONTROL
The air mix doors are automatically controlled so that in-vehicle temperature is maintained at a predetermined
value by the temperature setting, ambient temperature, in-vehicle temperature and amount of sunload.
BLOWER SPEED CONTROL
Blower speed is automatically controlled by the temperature setting, ambient temperature, in-vehicle tempera-
ture, intake temperature, amount of sunload and air mix door position.
When AUTO switch is pressed, the blower motor starts to gradually increase air flow volume (if required).
When engine coolant temperature is low, the blower motor operation is delayed to prevent cool air from flow-
ing.
INTAKE DOOR CONTROL
The intake door is automatically controlled by the temperature setting, ambient temperature, in-vehicle tem-
perature, intake temperature, amount of sunload and the ON-OFF operation of the compressor.
MODE DOOR CONTROL
The mode door is automatically controlled by the temperature setting, ambient temperature, in-vehicle temper-
ature, intake temperature and amount of sunload.
DEFROSTER DOOR CONTROL
The defroster door is controlled by: Turning the defroster dial to front defroster.
TROUBLE DIAGNOSIS
ATC-81
C
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MA
B
AT C
SYSTEM DESCRIPTION
Component Parts
Blower speed control system components are:
lFront air control
lIn-vehicle sensor
lAmbient sensor
lOptical sensor
lIntake sensor
System Operation
Automatic Mode
In the automatic mode, the blower motor speed is calculated by the front air control and variable blower control
based on input from the in-vehicle sensor, optical sensor, intake sensor and ambient sensor, and potentio tem-
perature control (PTC).
When the air flow is increased, the blower motor speed is adjusted gradually. to prevent a sudden increase in
air flow.
In addition to manual air flow control and the usual automatic air flow control, starting air flow control, low
water temperature starting control and high passenger compartment temperature starting control are avail-
able.
Starting Blower Speed Control
Start up from cold soak condition (Automatic mode).
In a cold start up condition where the engine coolant temperature is below 50°C(122°F), the blower will not
operate at blower speed 1 for a short period of time (up to 210 seconds). The exact start delay time varies
depending on the ambient and engine coolant temperatures.
In the most extreme case (very low ambient temperature) the blower starting delay will be 210 seconds as
described above. After the coolant temperature reaches 50°C(122°F), or the 210 seconds has elapsed, the
blower speed will increase to the objective blower speed.
Start up from usual operating or hot soak condition (Automatic mode).
The blower will begin operation momentarily after the AUTO switch is pushed. The blower speed will gradually
rise to the objective speed over a time period of 3 seconds or less (actual time depends on the objective
blower speed).
WJIA1252E
ATC-100
TROUBLE DIAGNOSIS
Insufficient Heating
EJS006BS
SYMPTOM: Insufficient heating
INSPECTION FLOW
*1ATC-57, "Operational Check".*2AT C - 6 8 , "Air Mix Door Motor Circuit".*3ATC-55, "A/C System Self-diagno-
sis Function".
*4ATC-55, "
A/C System Self-diagnosis
Function".*5AT C - 8 0 , "
Blower Motor Circuit".*6EC-103, "DTC P0117, P0118 ECT
SENSOR".
*7CO-7, "
Changing Engine Coolant".*8CO-13, "Checking Reservoir Tank
Cap".
MJIB0350E
ATC-126
HEATER & COOLING UNIT ASSEMBLY
Removal and Installation
EJS006C9
REMOVAL
1. Discharge the refrigerant from the A/C system. Refer toATC-138, "Discharging Refrigerant".
2. Drain the coolant from the engine cooling system. Refer toCO-8, "
DRAINING ENGINE COOLANT".
3. Remove the heater core pipes RH nut.
4. Disconnect the heater core hoses from the heater core.
5. Disconnect the high- and low-pressure A/C pipes from the
expansion valve.
6. Move the two front seats to the rearmost position on the seat
track.
7. Remove the instrument panel and console panel. Refer toIP-10,
"Removal and Installation".
8. Remove the two front floor ducts.
9. Remove the steering column. Refer toPS-10, "
Removal and
Installation".
10. Disconnect the instrument panel wire harness at the RH and LH in-line connector brackets, and the fuse
block (SMJ) electrical connectors. Refer toPG-38, "
Harness Layout".
11. Remove the covers then remove the three steering member bolts from each side to disconnect the steer-
ing member from the vehicle body.
12. Remove the heater and cooling unit assembly with it attached to the steering member, from the vehicle.
CAUTION:
lUse care not to damage the seats and interior trim panels when removing the heater and cooling
unit assembly with it attached to the steering member.
lUse suitable plugs on the heater core pipes to prevent coolant leakage.
13. Remove the heater and cooling unit assembly from the steering member.
INSTALLATION
Installation is in the reverse order of removal.
CAUTION:
lReplace the O-ring of the low-pressure A/C pipe and high-pressure A/C pipe with a new one, and
apply compressor oil to the O-ring for installation.
lAfter charging the refrigerant, check for leaks. Refer toATC-150, "Checking for Refrigerant Leaks"
.
NOTE:
lFill the engine cooling system with the specified coolant mixture. Refer toCO-8, "REFILLING ENGINE
COOLANT".
lRecharge the A/C system. Refer toATC-138, "Evacuating System and Charging Refrigerant".
LJIA0165E
ATC-128
HEATER PUMP
HEATER PUMP
PFP:92264
ComponentsEJS006CC
Heater Pump
Removal and InstallationEJS006DC
REMOVAL
1. Partially drain the engine cooling system. Refer toCO-8, "DRAINING ENGINE COOLANT".
2. Disconnect the heater pump electrical connector.
3. Disconnect the two heater hoses.
4. Remove the heater pump from the bracket securing the heater pump to the cowl top.
CAUTION:
Do not disassemble the heater pump, replace the heater pump as an assembly.
INSTALLATION
Installation is in the reverse order of removal.
CAUTION:
lThe heater pump rubber mount must be fully seated on the bracket.
lDo not disassemble the heater pump, replace the heater pump as an assembly.
LBIA0414E
1. Cowl top 2. Heater pump electrical connector 3. Heater pump
4. Heater hose 5. Heater hose
CO-1
ENGINE COOLING SYSTEM
B ENGINE
CONTENTS
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SECTIONCO
A
CO
ENGINE COOLING SYSTEM
PRECAUTIONS .......................................................... 2
Precautions For Liquid Gasket ................................. 2
LIQUID GASKET APPLICATION PROCEDURE..... 2
PREPARATION ........................................................... 3
Special Service Tools ............................................... 3
Commercial Service Tools ........................................ 3
OVERHEATING CAUSE ANALYSIS .......................... 4
Troubleshooting Chart .............................................. 4
COOLING SYSTEM .................................................... 6
Cooling Circuit .......................................................... 6
ENGINE COOLANT .................................................... 7
Inspection ................................................................. 7
LEVEL CHECK ..................................................... 7
CHECKING RADIATOR SYSTEM FOR LEAKS..... 7
Changing Engine Coolant ........................................ 7
DRAINING ENGINE COOLANT ........................... 8
REFILLING ENGINE COOLANT .......................... 8
FLUSHING COOLING SYSTEM ........................... 9
RADIATOR .................................................................11
Components ............................................................ 11
Removal and Installation ......................................... 11
REMOVAL ............................................................ 11
INSPECTION AFTER REMOVAL ....................... 13
INSTALLATION ................................................... 14
INSPECTION AFTER INSTALLATION ............... 14
RADIATOR (ALUMINUM TYPE) .............................. 15
Components ........................................................... 15
Disassembly and Assembly ................................... 15
PREPARATION ................................................... 15
DISASSEMBLY ................................................... 15
ASSEMBLY ......................................................... 16
INSPECTION ...................................................... 18COOLING FAN .......................................................... 19
Components (Crankshaft Driven Type) .................. 19
Removal and Installation ........................................ 19
REMOVAL ........................................................... 19
INSPECTION AFTER REMOVAL ....................... 19
INSTALLATION ................................................... 19
Removal and Installation (Motor Driven Type) (Mod-
els with A/C) ........................................................... 19
REMOVAL ........................................................... 19
INSTALLATION ................................................... 20
WATER PUMP .......................................................... 21
Components ........................................................... 21
Removal and Installation ........................................ 21
REMOVAL ........................................................... 21
INSPECTION AFTER REMOVAL ....................... 22
INSTALLATION ................................................... 22
INSPECTION AFTER INSTALLATION ................ 22
THERMOSTAT AND WATER PIPING ...................... 23
Components ........................................................... 23
Removal and Installation ........................................ 24
REMOVAL ........................................................... 24
INSPECTION AFTER REMOVAL ....................... 24
INSTALLATION ................................................... 24
INSPECTION AFTER INSTALLATION ................ 25
SERVICE DATA AND SPECIFICATIONS (SDS) ...... 26
Standard and Limit .................................................. 26
ENGINE COOLANT CAPACITY .......................... 26
THERMOSTAT .................................................... 26
RESERVOIR TANK ............................................. 26
CO-2
PRECAUTIONS
PRECAUTIONS
PFP:00001
Precautions For Liquid GasketEBS01E6J
LIQUID GASKET APPLICATION PROCEDURE
1. Remove old liquid gasket adhering to the liquid gasket application surface and the mating surface.
lRemove liquid gasket completely from the liquid gasket application surface, mounting bolts, and bolt
holes.
2. Wipe the liquid gasket application surface and the mating surface with white gasoline (lighting and heating
use) to remove adhering moisture, grease and foreign materials.
3. Attach liquid gasket tube to the tube presser [SST].
Use Genuine Liquid Gasket or equivalent.
lWithin five minutes of liquid gasket application, install the mat-
ing component.
lIf liquid gasket protrudes, wipe it off immediately.
lDo not retighten mounting bolts or nuts after the installation.
lAfter 30 minutes or more have passed from the installation, fill
engine oil and engine coolant.
PBIC2160E
CO-4
OVERHEATING CAUSE ANALYSIS
OVERHEATING CAUSE ANALYSIS
PFP:00012
Troubleshooting ChartEBS01E6M
Symptom Check items
Cooling sys-
tem parts
malfunctionPoor heat transferWater pump malfunction Worn or loose drive belt
— Thermostat stuck closed —
Damaged finsDust contamination or
paper clogging
Physical damage
Clogged radiator cooling
tubeExcess foreign material
(rust, dirt, sand, etc.)
Reduced air flowCooling fan does not oper-
ateRefer toEC-132, "
DTC
P0217 ENGINE OVER
TEMPERATURE"
—
Highresistancetofanrota-
tion
Fan assembly
Damaged fan blades
Damaged radiator shroud — — —
Improper engine coolant
mixture ratio—— —
Poor engine coolant quality — Engine coolant density —
Insufficient engine coolantEngine coolant leaksCooling hoseLoose clamp
Cracked hose
Water pump Poor sealing
Radiator capLoose
Poor sealing
RadiatorO-ring for damage, deterio-
ration or improper fitting
Cracked radiator tank
Cracked radiator core
Reservoir tank Cracked reservoir tank
Overflowing reservoir tankExhaust gas leaks into
cooling systemCylinder head deterioration
Cylinder head gasket dete-
rioration