Page 100 of 751
03-232210-01
Accelerator pedal position
sensor
Detecting driver's intention
for speed up/down
Fuel rail assembly
Relieving the pulsation.
Measuring the fuel pressure.
Distributing the fuel to injectors.
Fuel filter assembly
Supplying clean fuel/fuel
heating/water separation by
priming pump
Plunger type HP pump (1,800 bar)
Vane type LP pump (6 bar)
T-MAP sensor
Measuring booster pressure
and temperature
High pressure pump
Generating high pressurized fuel and
supplying it according to engine rpm,
required volume, required pressure
Page 142 of 751

08-4
2. INSPECTION
Problem Possible Cause Action
Coolant level is
too low- Leak from the radiator
- Leak from the coolant auxiliary tank
- Leak from the heater core- Change the radiator
- Change the coolant auxiliary tank
- Change the heater
- Leak from the coolant hose
connections
- Damaged coolant hose- Reconnect the hose or replace
the clamp
- Change the hose
- Leak from the water pump gasket
- Leak from the water pump internal
seal- Change the gasket
- Change the water pump
- Leak from the water inlet cap
- Leak from the thermostat housing- Change the water inlet cap
gasket
- Change the thermostat sealing
- Incorrect tightening torque of the
cylinder head bolts
- Damaged cylinder head gasket- Tighten the bolts to the specified
torque
- Change the cylinder head gasket
Coolant
temperature is
too high- Coolant leakage (Coolant level is low)
- Improper coolant mixture ratio
- Kinked coolant hose- Add coolant
- Check the coolant concentration
(Anti-freeze)
- Repair or replace the hose
- Defective thermostat
- Defective water pump
- Defective radiator
- Defective coolant auxiliary tank or
tank cap- Change the thermostat
- Change the water pump
- Change the radiator
- Change the coolant auxiliary tank
or tank cap
- Cracks on the cylinder block or
cylinder head
- Clogged coolant passages in the
cylinder block or cylinder head- Change cylinder block or cylinder
head
- Clean the coolant passage
- Clogged radiator core - Clean the radiator core
- Improper operation of cooling fan - Replace the cooling fan or repair
the related circuit
- Defective temperature sensor or
faulty wiring- Replace the sensor or repair the
related wiring
Coolant
temperature is
too low- Thermostat is stuck open - Change the thermostat
- Improper operation of cooling fan - Replace the cooling fan or repair
the related circuit
- Defective temperature sensor or
faulty wiring- Replace the sensor or repair the
related wiring
Page 145 of 751

08-71520-00
3. CAUTIONS
If 100% of anti-freeze is added, the water pump vane can be damaged and thermal conductivity
can be decreased resulting in poor circulation in the cooling system which leads to overheated
engine.
Use of non-recommended coolant could cause damage to the cooling system and overheating of
the engine.
Opening the coolant reservoir cap while the engine is running or hot can cause burns by hot steam
or water.
To open the coolant reservoir cap, wrap the cap with a wet towel or thick cloth after the engine is
cooled down sufficiently.
If cool water is added to the heated engine, the engine or radiator can be deformed.
The anti-freeze in the coolant can damage the painted surface, so avoid the contact of the coolant
to the painted body.
The anti-freeze and water should be mixed in proper mixture ratio. Never add only water when
adding coolant.
If the anti-freeze content is too low, the coolant can be frozen while the engine can be overheated if
anti-freeze content is too high. -
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Page 146 of 751
08-8
Oil filter module
Thermostat
When the engine coolant
reaches 90℃, the thermostat
starts to open (fully open at
100℃) and lets the coolant
flow to the radiator to maintain
the engine temperature.
Water pump
The water pump is driven by the engine drive belt and supplies
the coolant to each area of the engine.
Coolant reservoir
Long life coolant is used.
1. SYSTEM DESCRIPTION
1) Overview
Water pump
Impeller vane Sealing
Page 239 of 751

15-390000-00
HFM (intake air
temperature)Cooling fan
module
DSI 6 A/T (ATF
temperature)Coolant
temperature
sensor
Refrigerant
pressure sensor
Relay box
(12) Cooling fan control
A. Overview of cooling fan and A/C compressor
The cooling system maintains the engine temperature at an efficient level during all engine operating
conditions. The water pump draws the coolant from the radiator. The coolant then circulates through
water jackets in the engine block, the intake manifold, and the cylinder head. When the coolant reaches
the operating temperature of the thermostat, the thermostat opens. The coolant then goes back to the
radiator where it cools. The heat from automatic transmission is also cooled down through the radiator
by circulating the oil through the oil pump. ECU controls the electric cooling fans with three cooling fan
relays to improve the engine torque and air conditioning performance.
For detailed information, refer to Chapter "Air Conditioning System".
B. Components
A/C compressor
D20DTR ECU
Page 283 of 751
06-32110-01
1. GENERAL SPECIFICATIONS
Application Gasoline engine
Cooling system Type Water cooling forced circulation
Coolant Capacity 11.3L
Thermostat Type Wax Pellet Type
Initial Opening Temp.87℃(188.6℉)
Fully Opening Temp.102℃(215.6℉)
Fully Closing Temp.85℃(187℉)
Stroke 7mm
Cooling fan module Type Electric
CapacityΦ472 x 400W x 5B
Control type PWM type
Coolant reservoir Capacity over 1.5L
Circulation Closed roof type
Pressure cap Screw type, 1.4bar
Vacuum valve Screw type, 1.4bar
Water pump Type Turbo centrifugal
Impeller diameter 65mm
Impeller blades 8
Radiator Core size555W x 582.4H x 27T (over 326,250mm²)
Flow type Cross flow
Min. cooling capacity over 68,000kcal/h
Coolant temperature
gaugeMinimum radiation capability 45,000kcal/h
Resistance(50℃(122℉)) 185.2Ω
Resistance(80℃(176℉)) 47.4Ω
Resistance(105℃(221℉)) 28.2Ω
Page 286 of 751

06-6
2. DESCRIPTION AND OPERATION
1) General Description
The cooling system maintains the engine temperature at an efficient level during all engine operating
conditions.
When the engine is cold, the cooling system cools the engine slowly or not at all. This slow cooling o
f
the engine allows the engine to warm up quickly.
The cooling system includes a radiator and recovery subsystem, cooling fans, a thermostat and
housing, a water pump, and a water pump drive belt. The timing belt drives the water pump.
All components must function properly for the cooling system to operation. The water pump draws the
coolant from the radiator. The coolant then circulates through water jackets in the engine block, the
intake manifold, and the cylinder head. When the coolant reaches the operating
temperature of the thermostat, the thermostat opens. The coolant then goes back to the radiator where
it cools.
This system directs some coolant through the hoses to the heat core. This provides for heating and
defrosting.
The coolant reservoir is connected to the radiator to recover the coolant displaced by expansion from
the high temperatures. The coolant reservoir maintains the correct coolant level.
The cooling system for this vehicle has no radiator cap or filler neck. The coolant is added to the cooling
system through the coolant reservoir.
2) Radiator
This vehicle has a lightweight tube-and-fin aluminum radiator. Plastic tanks are mounted on the upper
and the lower sides of the radiator core.
On vehicles equipped with automatic transaxles, the transaxle fluid cooler lines run through the radiato
r
tank.
A radiator drain plug is on this radiator.
To drain the cooling system, open the drain plug.
3) Coolant Reservoir
The coolant reservoir is a transparent plastic reservoir, similar to the windshield washer reservoir.
The coolant reservoir is connected to the radiator by a hose and to the engine cooling system by anothe
r
hose.
As the vehicle is driven, the engine coolant heats and expands. The portion of the engine coolant
displaced by this expansion flows from the radiator and the engine into the coolant reservoir. The ai
r
trapped in the radiator and the engine is degassed into the coolant reservoir.
When the engine stops, the engine coolant cools and contracts. The displaced engine coolant is then
drawn back into the radiator and the engine. This keeps the radiator filled with the coolant to the desired
level at all times and increases the cooling efficiency.
Maintain the coolant level between the MIN and MAX marks on the coolant reservoir when the system is
cold.
Page 287 of 751

06-72112-01
4) Water Pump
The belt-driven centrifugal water pump consists of an impeller, a drive shaft, and a belt pulley.
The impeller is supported by a completely sealed bearing.
The water pump is serviced as an assembly and, therefore, cannot be disassembled.
5) Thermostat
A wax pellet-type thermostat controls the flow of the engine coolant through the engine cooling system.
The thermostat is mounted in the thermostat housing to the front of the cylinder head.
The thermostat stops the flow of the engine coolant from the engine to the radiator to provide faste
r
warm-up, and to regulate the coolant temperature. The thermostat remains closed while the engine
coolant is cold, preventing circulation of the engine coolant through the radiator. At this point, the engine
coolant is allowed to circulate only throughout the heater core to warm it quickly and evenly.
As the engine warms, the thermostat opens. This allows the engine coolant to flow through the radiato
r
wherethe heat is dissipated. This opening and closing of the thermostat permits enough engine coolant
to enter the radiator to keep the engine within proper engine temperature operating limits.
The wax pellet in the thermostat is hermetically sealed in a metal case. The wax element of the
thermostat expands when it is heated and contracts when it is cooled.
As the vehicle is driven and the engine warms, the engine coolant temperature increases. When the
engine coolant reaches a specified temperature, the wax pellet element in the thermostat expands and
exerts pressure against the metal case, forcing the valve open. This allows the engine coolant to flow
through the engine cooling system and cool the engine.
As the wax pellet cools, the contraction allows a spring to close the valve.
The thermostat begins to open at 87°C(188.6 °F) and is fully open at 102°C(215.6°F). The
thermostat closes at 85°C (187°F).
6) Electric Cooling Fan
Keep hands, tools, and clothing away from the engine cooling fans to help prevent personal injury.
This fan is electric and can turn on even when the engine is not running. -
If a fan blade is bent or damaged in any way, no attempt should be made to repair or reuse the
damaged part. A bent or damaged fan assembly should always be replaced with a new one to
prevent possible injury. -