sensor SSANGYONG NEW REXTON 2012 Manual PDF

D. Bypass control for EGR cooler
Cooler temperature
Exhaust gas temperature
Otherwise, PM could be increased due to too low exhaust gas temperature.
E. Control elements for EGR system
Accelerator pedal (engine load) - Indicates the driver's intention and engine load. If the load goes up,
the EGR ratio is decreased.
T-MAP (boost pressure map stored in ECU) - Compensates the difference in boost pressure by
adjusting EGR ratio.
Engine rpm - Used as the signal for determining EGR operating range.
Coolant temperature - When the coolant temperature is low, NOx is decreased but PM could be
increased. So, to reduce PM, decrease EGR ratio when the coolant temperature is low.
Intake air mass and temperature - HFM sensor measures the intake air mass to calculate the actual
EGR volume. If the air mass is larger than programmed value in map, EGR ratio will be higher.
EGR position sensor - Detects the actual opening angle of EGR valve and performs feedback
function according to PWM control by ECU.
Wide band oxygen sensor - Detects the oxygen volume in exhaust gas to check if the EGR ratio is
proper.
Electronic throttle body - Keeps EGR ratio to optimized level by controlling the throttle body in EGR
operating range (decreasing pressure in intake manifold). -
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(10) E-VGT control
A. Overview
E-VGT (Electric-Variable Geometry Turbine) turbocharger system in D20DTF engine uses the venturi
effect that controls the flow rate of exhaust gas by adjusting the passage in turbine housing. The newly
adopted DC motor actuator (E-actuator) controls the E-VGT system more precisely and faster. To get
the high operating power from turbine, the ECU reduces the exhaust gas passage In low speed range
and increases it in high speed range.
B. Components
HFM (intake air
temperature)E-VGT actuatorAccelerator pedal
module
Crankshaft
position sensorOxygen sensor
T-MAP sensor
Coolant
temperature
sensor
D20DTR ECU
Front EGT sensor

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HFM (intake air
temperature)CDPF
Electric throttle
bodyCoolant
temperature
sensorOxygen sensor
Injector (C3I)
E-EGR valve
(11) Wide band oxygen sensor control
A. Overview
For diesel engine, combustion is not performed at the optimum (theoretically correct) air-fuel ratio and
the oxygen concentration is thin in most cases. So the wide-band oxygen sensor is used for this kind of
engine, and this sensor is a little different from the one that used for gasoline engine. The combustion in
diesel engine is controlled by fuel injection volume. Therefore, the wide band oxygen sensor should be
used in diesel engine. This sensor measures the air-fuel ratio in very wide range, and is also called full
range oxygen sensor.
The wide band oxygen sensor measures the oxygen density in exhaust gas and sends it to ECU to
control the EGR more precisely. -
B. Components
D20DTR ECU

C. Input/Output for oxygen sensor

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D. Oxygen sensor control
The wide band oxygen sensor uses ZnO2. It produces the voltage by movement of oxygen ions when
there is oxygen concentration difference between exhaust gas and atmosphere.
If a certain voltage is applied to the sensor, the movement of oxygen ions occurs regardless of the
oxygen density. The current generated through this flow of ions, is called pumping current (IP), and the
oxygen sensor measures this value.

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

D. Cooling fan and A/C compressor control
Conditions for cooling fan
The cooling fan module controls the cooling fan relay, high speed relay and low speed relay. The cooling
fan is controlled by the series and parallel circuits.
A/C switch Cooling fanCoolant temperature Refrigerant pressure
A/C
compressor
OFF OFF
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LO
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HI
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ONLO
Refrigerant pressure <
18 bar
ON
HI
pressure
HI
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HI
-
OFF (cut)
A/C compressor OFF conditions
Approx. 4 seconds after starting the engine
Engine rpm: below 650 rpm or over 4500 rpm
When abrupt acceleration
Refrigerant pressure:
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The output voltage from refrigerant pressure sensor is 1.7 V to 3.5 V when the refrigerant pressure is 10
Output voltage according to refrigerant pressure
Cooling fan controls according to ATF
ATF temperature Fan condition Remark
High speed -

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(13) PTC heater control
A. Overview
The supplementary electrical heater is installed in DI engine equipped vehicle as a basic equipment. The
PTC system is operated according to two temperature values measured at the coolant temperature
sensor and HFM sensor. This device is mounted in the heater air outlet and increase the temperature of
air to the passenger compartment. Because PTC system is heated by electrical power, high capacity
alternator is required. PTC does not operate during engine cranking, while the battery voltage is lower
than 11 V or during preheating process of glow plugs.
B. Components
HFM (intake air
temperature)
Coolant temperature
sensorPTC heaterD20DTR ECU
PTC 1 relay
PTC 2 relay
PTC 3 relay
PTC Fuse 3 (40A)PTC Fuse 2 (40A)PTC Fuse 1(40A)
Relay box in engine compartment

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D. 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)
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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) -
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(15) CDPF control
A. Overview
As the solution for environmental regulations and PM Particle Material) of diesel engine, the low emission
vehicle is getting popular. This vehicle is equipped with an extra filter to collect the soot and burn it again
so that the amount of PM in the exhaust gas passed through the DOC (Diesel Oxidation Catalyst) is
reduced. The CDPF (Catalyst & Diesel Particulate Filter) is an integrated filter including DOC (Diesel
Oxidation Catalyst) and DPF (Diesel Particulate Filter).
For details, refer to Chapter "CDPF".
B. Components
Oxygen
sensorFront
EGT sensorCDPF
(DOC + DPF)Rear
EGT sensor
Differential pressure
sensorD20DTR ECUElectric throttle body