2012 SSANGYONG RODIUS fuel pressure

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LoadEngine
speedSwirl valve Amount of
swirlRemarks
Low speed,
Low loadbelow
3,000 rpmClosed HeavyIncreased EGR ratio, better air-fuel
mixture (reduce exhaust gas)
High speed,
High loadover 3,000
rpmOpen 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
3) 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. -
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4) Relationship Between Swirl and Fuel Injection Pressure
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.

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Overload of CDPF
(warning lamp blinking)Excessive overload of CDPF
(warning lamp illuminated)
(3) Warning Lamp Related to CDPF
CDPF regeneration process (warning lamp NOT illuminated) ▶
The CDPF system enters the regeneration mode
when the driving distance becomes approx. 600
to 1,200 km (may differ by the driving condition
and driving style). Then, the engine ECU
performs the CDPF regeneration operation.
However, the driver is not informed with this
operation by any engine warning lamp or
vehicle signal, so he/she may not detect this
operation. The control logic at the post-
injection dur-ing the regeneration process is to
increase the fuel injection volume and control
the intake air volume (by the throttle body) in
order to increase the temperature of the exhaust
gas. The driver may not feel any particular
difference from the vehicle.
If the CDPF cannot reach the regeneration
temperature due to low speed driving or other
reason during the regeneration process, the
soot is continuously accumulated in the CDPF.
When this condition continues and the CDPF is
overloaded with soot, the engine warning lamp
blinks to inform this situation to the driver.
In order to solve this problem, drive the vehicle
at a speed of approx. 80 km/h for 15 to 20
minutes to perform the CDPF regeneration
process.
If the engine warning lamp on the instrument
cluster blinks, the CDPF is overloaded. In this
case, perform the step 2. 1.
2.
3.If the vehicle is driven at a speed of 5 to 10
km/h for an extended period of time, the soot
accumulated in the CDPF cannot be burned as
the CDPF cannot reach the regeneration
temperature. Then, an excessive amount of
soot can be accumulated in the CDPF.
This case is much worse than the simple over-
load of the CDPF. To inform this to the driver,
the engine warning lamp comes on and the
engine power is decreased to protect the
system.
To solve this problem, blow soot between the
engine and exhaust system several times and
erase the related DTC. Then, check if the same
DTC is regenerated again. If so, check the DTC
related to the differential pressure sensor. 1.
2.
3.
OFF
BlinkingIlluminating

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3. INPUT/OUTPUT DEVICES
Front temperature sensor: This sensor is installed at the inlet of DOC and detects whether the
DOC can burn (oxidize) the post-injected fuel or not.
Rear temperature sensor: This sensor is installed at the inlet of DPF and monitors that the
temperature of the exhaust gas is kept at 600℃. 1.
2.
<0070008d0047009b008f008c0047009b008c00940097008c00990088009b009c0099008c0047008c009f008a008c008c008b009a0047005d005700570b4500530047009b008f008c004700930090008d008c00470096008d0047006a006b0077006d004700
8a0088009500470089008c00470099008c008b009c008a008c>d. So the amount of fuel
post-injection is decreased.
<0070008d0047009b008f008c0047009b008c00940097008c00990088009b009c0099008c0047008b009900960097009a0047009c0095008b008c00990047005d005700570b4500530047009b008f008c004700990088009b008c00470096008d0047009900
8c008e008c0095008c00990088009b0090009600950047008a>an be decreased. So the
amount of fuel post-injection is increased. -
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Differential pressure sensor: This sensor checks the amount of PM collected by calculating the
pressure difference between before and after the CDPF.
Electric throttle valve: This valve reduces the intake air flow to raise the temperature of the
exhaust gas when the CDPF is operating during idling. 3.
4.

14-8
4. POST-INJECTION AND AIR MASS CONTROL
A DPS (Differential Pressure Sensor) measures the pressure difference between before and after
the CDPF and detects whether the soot is collected in the CDPF or not. If PM is collected in the
CDPF (In this case the pressure difference between before and after the CDPF exceeds the
specified value. Normally, the system sends the signal when the driving distance becomes approx.
600 to 1,200 km), the temperature of exhaust gas is increased and the post-injection is started for
regeneration. The amount of fuel post-injection is controlled by the exhaust gas temperature
<0094008c0088009a009c0099008c008b0047008900a00047009b008f008c00470099008c008800990047009b008c00940097008c00990088009b009c0099008c0047009a008c0095009a00960099005500470070008d0047009b008f008c0047009b008c00
940097008c00990088009b009c0099008c00470090009a0047>less than 600℃, the amount of
post-injection is increased to increase the regeneration temperature. Otherwise, the fuel injection
amount is decreased or the fuel is not injected.
When the engine is running with low load, the intake air amount is also controlled as well as fuel
injection amount. This function is used to increaser the combustion temperature by increasing the
amount of fuel post-injection with the lowest air amount within the specified control logic.

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Rear temperature sensor
Measure the outlet
temperature of DOC.
This sensor is located at
the rear side of DOC and
monitors the overheating of
CDPF and post injection
volume.
Differential pressure sensor
Measures the difference between
inlet and outlet pressures of
CDPF.
If the difference is higher than the
specified value when collecting
the PM, this makes the post
injection for forced recycling of
PM.
Front temperature sensor
Measures the temperature of
exhaust gas.
This sensor is located at the rear
side of exhaust manifold and
monitors the temperature of
combusted gas to prevent the
exhaust system from overheating.
When the temperature gets
higher, this sensor cuts off the
fuel delivery and controls the EGR
to lower the temperature.
Engine ECU (D20DTR)
T-MAP sensorIntake air
mass
Measures
the
excessive
amount of
PM.
Injector (C31)
Controls the post injection.
Electric throttle body
Controls the intake air
mass.
HFM sensor
Wide band
oxygen
sensor
Boost
pressure/
temperature

15-6
Fuel Rail Pressure SensorFront EGT Sensor
Differential Pressure SensorCamshaft Position SensorRear EGT Sensor

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Fuel rail pressure Water sensor
(2) Components for ECU Input
CAN
- ABS & ESP
- GCU
- Indicator/
Warning Lamp,
Meter Cluster
- TCUSwirl valve
position
sensor
Differential
pressure sensorE-EGR valve
position
sensorCamshaft position
sensorCoolant
temperature
sensor
EGT sensorHFM sensorOxygen sensorT-MAP sensor
Crankshaft
position
sensorAccelerator pedal
sensorThrottle
position
sensorKnock sensor
- Auto cruise switch
- Refrigerant pressure
sensor
- Blower switch signal
- Brake pedal signal

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2) ECU Control
(1) Function
a. ECU Function
ECU receives and analyzes signals from various sensors and then modifies those signals into
permissible voltage levels and analyzes to control respective actuators.
ECU microprocessor calculates injection period and injection timing proper for engine piston speed and
crankshaft angle based on input data and stored specific map to control the engine power and emission
gas.
Output signal of the ECU microprocessor drives pressure control valve to control the rail pressure and
activates injector solenoid valve to control the fuel injection period and injection timing; so controls
various actuators in response to engine changes. Auxiliary function of ECU has adopted to reduce
emission gas, improve fuel economy and enhance safety, comforts and conveniences. For example,
there are EGR, booster pressure control, autocruise (export only) and immobilizer and adopted CAN
communication to exchange data among electrical systems (automatic T/M and brake system) in the
vehicle fluently. And Scanner can be used to diagnose vehicle status and defectives.
<00760097008c00990088009b00900095008e0047009b008c00940097008c00990088009b009c0099008c0047009900880095008e008c00470096008d0047006c006a007c00470090009a0047009500960099009400880093009300a000470054005b005700
47009b009600470052005f005c00b6006a004700880095008b> protected from factors like oil,
water and electromagnetism and there should be no mechanical shocks.
To control the fuel volume precisely under repeated injections, high current should be applied instantly
so there is injector drive circuit in the ECU to generate necessary current during injector drive stages.
Current control circuit divides current applying time (injection time) into full-in-current-phase and hold-
current-phase and then the injectors should work very correctly under every working condition.
b. Control Function
Controls by operating stages
To make optimum combustion under every operating stage, ECU should calculate proper injection
volume in each stage by considering various factors.
Starting injection volume control
During initial starting, injecting fuel volume will be calculated by function of temperature and engine
cranking speed. Starting injection continues from when the ignition switch is turned to ignition
position to till the engine reaches to allowable minimum speed.
Driving mode control
If the vehicle runs normally, fuel injection volume will be calculated by accelerator pedal travel and
engine rpm and the drive map will be used to match the drivers inputs with optimum engine power. -
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