Page 352 of 796

15-24
(8) Swirl control
A. Overview
Variable swirl valve ▶
The strong swirl caused by intake air is important element for anti-locking function in diesel engine. The
swirl control valve partially closes the intake port to generate the swirl according to the engine
conditions. When the engine load is in low or medium range, the swirl could not be generated because
the air flow is slow. To generate strong swirl, there are two passages in intake manifold, and one of
them has the valve to open and close the passage. When the valve closes the passage, the air flow
through the another passage will be faster, and the strong swirl will be generated by the internal
structure of the passage. This swirl makes the better mixture of air and fuel, eventually the combustion
efficiency in combustion chamber could be improved. This provides the enhanced fuel consumption,
power and EGR ratio.
Components ▶
HFMCrankshaft position sensorVariable swirl valve
Coolant temperature
sensorAccekerator pedal
moduleD20DTR ECU
Page 355 of 796

15-270000-00
Load Engine speedSwirl
valveAmount of
swirlRemarks
Low speed,
Low loadbelow 3,000 rpm Closed HeavyIncreased EGR ratio, better air-fuel
mixture (reduce exhaust gas))
High speed,
High loadover 3,000 rpm Open LightIncrease charge efficiency, higher
engine power
The variable swirl valve actuator operates when
turning the ignition switch ON/OFF position to
open/close the swirl valve. In this period, the
soot will be removed and the learning for swirl
valve position is performed.
Swirl: This is the twisted (radial) air flow along the cylinder wall during the intake stroke. This
stabilizes the combustion even in lean air-fuel mixture condition.
Swirl valve
E. Features
Swirl and air intake efficiency
To generate the swirl, the intake port should be serpentine design. This makes the resistance in air
flow. The resistance in air flow in engine high speed decreases the intake efficiency. Eventually, the
engine power is also decreased, Thus, the swirl operation is deactivated in high speed range to
increase the intake efficiency.
Relationship between swirl and EGR
To reduce Nox, it is essential to increase EGR ratio. However, if EGR ratio is too high, the PM also
could be very higher. And, the exhaust gas should be evenly mixed with newly aspired air.
Otherwise, PM and CO are dramatically increased in highly concentrated exhaust gas range and
EGR ratio could not be increased beyond a certain limit. If the swirl valve operates in this moment,
the limit of EGR ratio will be higher. -
-
F. Relationship between swirl and fuel injection pressur
The injector for DI engine uses the multi hole design. For this vehicle, there are 8 holes in injector. If the
swirl is too strong, the injection angles might be overlapped and may cause the increased PM and
insufficient engine power. Also, if the injection pressure is too high during strong swirl, the injection
angles might be overlapped. Therefore, the system may decreases the fuel injection pressure when
the swirl is too strong.
Page 366 of 796

15-38
Relay box
A/C
compressorHFM (intake air
temperature)Cooling fan
module
MB 5 A/T (ATF
temperature)Coolant
temperature
sensor
(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
D20DTR ECU
Refrigerant
Page 371 of 796
15-430000-00
C. PTC operation process
The PTC operating condition (ON) is controlled in two steps.
Basically, the engine ECU controls the relay to supply the power to PTC according to the coolant
temperature sensor and ambient temperature sensor.
1st step (initial operation of PTC) ▶
Coolant temperature < 15°C: PTC ON
Coolant temperature ≥ 15°C: PTC ON after satisfying the conditions in 2nd step -
-
2nd step (coolant temperature ≥ 15°C) ▶
Coolant temperature ≤ 65°C and intake air temperature ≤ -10°C: PTC ON
Coolant temperature < 60~65°C and intake air temperature < -10~0°C: PTC ON
Coolant temperature ≤ 60°C and intake air temperature ≤ 0~5°C: PTC ON -
-
-
Stop (OFF) conditions ▶
A/C blower switch OFF
Defective ambient air temperature sensor (including open or short circuit)
Engine cranking
Low battery voltage (below 11V)
During pre-glow process (glow indicator ON) -
-
-
-
-
Page 531 of 796

09-4
2. CAUTIONS
The parking aid system is just a supplemental device to help your parking.
Always keep the safety precautions.
Do not press or shock the sensors by hitting or using a high-pressure water gun while washing,
since it may damage the sensors.
If the system is in normal operating condition, a short beep sounds when the shift lever is moved
into "R" position with the ignition key "ON".
If the system is defective, the warning buzzer sounds for 3 seconds when moving the gear shift
lever to “R” position with the ignition ON. Be careful not to confuse this and the parking aid
alarm (in 50 cm). 1.
2.
3.
4.
5.
- Note that the display does not show everything in the rear area. Always check
nobody, especially animals and children, is behind the vehicle when parking or
reversing.
- If you can not properly check the vehicle behind, get out of the vehicle and then
visually check it.
The parking aid system will not work or improperly work under following cases: ▶
1) Certain obstacles that sensors can not detect
Thin and narrow objects, such as wires, ropes, chains
Cotton, sponge, clothes, snow; that absorb ultrasonic waves
Obstacles lower than the bumper (ex. drain ditch or mud puddle) -
-
-
2) Not defective but improperly working
When the sensing portion is frozen (operates normally after thawed)
When the sensing portion is covered by rain, water drops, snow or mud (operates normally after
cleaned)
When receiving other ultrasonic signals (metal sound or air braking noises from heavy commercial
vehicles)
When a high-power radio is turned on -
-
-
-
3) Narrowed sensing area
When the sensing portion is partially covered by snow or mud (operates normally after cleaned)
Surrounding temperature of sensor is too high (approx. over 80°C) or too low
(approx. below -30°C) -
-
4) Not defective but may cause malfunction
When driving on the rough roads, gravel road, hill and grass
When the bumper height is changed due to heavy load
When the sensing portion is frozen
When the sensing portion is covered by rain, water drops, snow or mud
When receiving other ultrasonic signals (metal sound or air braking noises from heavy commercial
vehicles)
When a high-power radio is turned on
When some accessories are attached in detecting ranges -
-
-
-
-
-
-
Page 680 of 796

10-74891-01
2) EBD (Electronic Brake Force Distribution) System
▶System description
As an add-on logic to the ABS base algorithm, EBD works in a range in which the intervention
thresholds for ABS control are not reached yet.
EBD ensures that the rear wheels are sensitively monitored for slip with respect to the front axle. If slip
is detected, the inlet valves for the rear wheels are switched to pressure hold to prevent a further
increase in pressure at the rear-wheel breaks, thus electronically reproducing
a pressure-reduction function at the rear-wheel brakes.
ABS features an enhanced algorithm which includes control of the brake force distribution between the
front and rear axles. This is called Electronic Brake Distribution. In an unloading car condition the brake
efficiency is comparable to the conventional system but for a fully loaded vehicle the efficiency of the
EBD system is higher due to the better use of rear axle braking capability.
▶Advantages
Elimination of conventional proportioning valve EBD utilizes the existing rear axle wheel speed
sensor to monitor rear wheel slip.
Based on many variables in algorithm a pressure hold, increase and/or decrease pulsetrain may
be triggered at the rear wheels insuring vehicle stability.
Vehicle approaches the ideal brake force distribution (front to rear).
Constant brake force distribution during vehicle lifetime.
EBD function is monitored via ABS safety logic (conventional proportioning valves are not
monitorable). -
-
-
-
-
3) Important Notice
The modulators for production line are not filled with the brake fluid (dry type). But, for after service, they
are filled with the brake fluid (wet type).
Make sure to keep the procedures in service manual when bleeding the air from the brake lines.
Be familiar with the lamp ON conditions to provide the correct information and reliability to customers.
ECU monitors the valve and motor for ABS when the vehicle speed approaches 5 km/h. At this time,
you can hear the clattering noise. 1.
2.
3.
Page 717 of 796
01-12
(2) Ventilation Modes
Vent mode * Bi-level mode*
Floor mode * Defrost and floor mode*
Defrost mode
*Rear air conditioning mode
*
Page 718 of 796
01-136810-30
2) Air Conditioner Module Wiring and Layout
(1) Front Air Conditioner Module
Air source selection
door actuator
Air conditioner
filterEvaporator
Blower motor
Blower high
speed relay
Heater core
Wiring layout
Components
Sun sensor
Interior temperature sensor
Front mode actuator
Air mix actuator
Duct temperature sensor
PTC heater A.
B.
C.
D.
E.
F.Thermo amplifier
Front power transistor
Front blower motorA/C filter
Air source mode actuator
Rear blower switch G.
H.
I.
J.
K.
M.