ECU SSANGYONG NEW REXTON 2012 Service Manual

2. ENGINE ACCESSORIES RELATED TO ECU
HFM sensor (HFM 6.0)
To control the engine more precisely, new
functions such as digital signal for intake air mass
have been introduced.
Engine ECU
Location

0000-00
2) Major Changes and Summary
D20DT Engine Remarks
Engine ECU - Version 3.2
ECU ECU version 3.2 in D20DT engine has
two connectors.
1. E-EGR valve system
2. Throttle body system
3. C3I injector system
Injector
C3I label
Layout of E-EGR system
Throttle body
E-EGR valve
EGR cooler
* Injection nozzle (hole): 7
* Injector label and coding
- D27DTP, D20DT
(20 digits: C3I coding)
* To meet the emission regulation,
especially for reducing NOx, same E-EGR
valve and EGR cooler in power-up engine
(Rexton II) have been introduced.

D20DT Engine Remarks
HFM 6.0 HFM 6-ID
(Added digital signal function) -
Electrically controlled E-EGR valveECU controls the EGR valve directly.
It provides precise EGR control by
transmitting the electric signal of EGR
valve operating position. *
Vacuum modulator
Vacuum modulator for
turbocharger control
The vacuum modulator for controlling
EGR valve has been deleted. *
Throttle body is used to prevent the
engine from turning off with fluttering
noise at the moment the air to intake
manifold is blocked by closed flap
when the engine is switched off. *
Throttle body

1. FUEL FLOW OF D20DT (EURO 4) ENGINE
According to input signals from various sensors, engine ECU calculates driver's demand (position of the
accelerator pedal) and then controls overall operating performance of engine and vehicle on that time. ECU
receives the signals from sensors via data line and then performs effective engine air-fuel ratio controls
based on those signals. Engine speed is measured by crankshaft speed (position) sensor and camshaft
speed (position) sensor determines injection order and ECU detects driver's pedal position (driver's
demand) through electrical signal that is generated by variable resistance changes in accelerator pedal
sensor. HFM (Hot Film Air Mass) sensor detects intake air volume and sends the signals to ECU.
Especially, the engine ECU controls the air-fuel ratio by recognizing instant air volume changes from air flow
sensor to decrease the emissions (EGR valve control). Furthermore, ECU uses signals from coolant
temperature sensor and air temperature sensor, booster pressure sensor and atmospheric pressure sensor
as compensation signal to respond to injection starting, pilot injection set values, various operations and
variables.

0000-00
1. COMPONENTS
1. E-EGR valve: Controlling the EGR valve electrically and sends the valve location signal to ECU
(vacuum modulator control has been deleted).
2. EGR cooler:
VGT turbochargerIntake manifold
Turbocharger intercooler
(intake air)
EGR gas (from EG
R
cooler)
E-EGR
valve
Exhaust manifoldE-EGR
valveCoolant
To intake
manifold
EGR cooler
EGR pipe
E-EGR valveDecreasing EGR gas (NOx) efficiently by cooling the EGR gas and let it flow to the
intake manifold. The components of the exhaust system consist of:
Throttle body
Exhaust manifold

1533-01
1. OVERVIEW FOR CDPF (EURO IV)
The CDPF (Catalyst & Diesel Particulate Filter) was installed to the Rexton II D27DTP engine previously.
However, it is now installed to the all 2009 DI engine models, except the Actyon Sports. The DI engine
type sinstalled to Rexton are D27DTP, D27DT and D20DT, and their CDPF, related sensor and
operation logic are the same.This section describes the CDPF system (based on Euro IV) which is
installed to the Rexton II D27DTPengine (older model).
1) General Description
2) Compatibility of CDPF System by Vehicle Model
Rexton II: Same CDPF system for D27DTP and D27DT engines (including its components)
Kyron & Actyon: Same CDPF system for D27DT and D20DT engines (including its components)
The CDPF assemblies installed to the Euro IV D27DTP Rexton II and 2009 Rexton II are
different in their mounting layout, but their front/rear exhaust temperature sensors and
differential pressure sensors are same. -
3) System Met with EURO IV Regulations
The Ssangyong vehicles installed with the D27DT engine manufactured from July 2007 to December
2007 comply with the EURO IV regulations. Modified components from the old engine model are as
follow:
- E-EGR valve
- EGR cooler
- Engine ECU (Ver. 3.2)
- HFM senso
- C3I injector
- Electronic throttle valve (body)
- Other engine mounting components
For details about the modified components and system related to the EURO IV regulations, refer to the
2008 Rodius engine service manual.

1533-01
Throttle Body
CDPF system controls the amount of intake air by controlling the
electronic throttle body. The electronic throttle body has the
following main functions.
CDPF control - added a function that increases the exhaust gas
temperature by closing the throttle valve flap to minimize the intake
air amount by the fuel injection amount during the CDPF
regeneration range with the low engine load range.
ON/OFF control - prevents the engine from turning off with
vibration and noise by closing the throttle body flap to block the
intake air when the engine is stopped.
Duty control - controls the valve inside the throttle body to burn
more EGR gas in the EGR valve operating range.
VGT Turbocharger and Front Exhaust Gas Temperature Sensor
Turbocharger may become weaker if high tem-
perature exhaust gas passes through the tur-
bocharger for DPF regeneration process.
The front exhaust gas temperature sensor moni-tors
the temperature of the exhaust gas that flows into the
turbocharger.
If the temperature of the exhaust gas that passes
through the exhaust manifold is higher than the
specification, the ECU decreases the fuel injection
amount and increases the EGR gas intake amount to
decrease the exhaust gas temperature.Front exhaust gas
temperature sensor

1533-01
2.CDPF (EURO IV) SYSTEM CONTROL
1) General Description
As the soot is filtered in the CDPF, it is burnt and removed, and the CDPF is returned to the initial state to
collect the soot. Therefore, the burning procedures in the CDPF can be called as regeneration.
The CDPF assembly is integrated with DOC (at front side) and DPF (at rear side).
The DPF burns the soot with high-temperature exhaust gas (over
The rear exhaust gas
temperature sensor monitors the temperature of DPF section. If this temperature is below the
regeneration temperature, the ECU increases the post injection period to increase the fuel injection
amount, and consequently to increase the exhaust gas temperature.
Front exhaust gas temperature sensor
(Measuring temperature of exhaust gas in
exhaust manifold)
Rear exhaust gas temperature sensor
(Measuring temperature of exhaust gas
escaping DOC)
Normally, when the vehicle is driven for 600 ~ 1,200 km, the enough amount of soot to be burnt is
filtered and accumulated in the CDPF. The ECU increase the amount of post injection to increase
the tempeature of exhaust gas up to
so that the soot is burnt. The soot is burnt for
15 ~ 20 minutes. -

1533-01
Throttle bodies by engine type
The throttle valve is controlled by electric signals sent from the engine ECU for optimal fuel
injection volume, engine load and effective combustion of EGR gas according to the Euro 4
regulations. It has following functions by the engine type. -

3. SOOT FILTERING AND BURNING PROCEDURES
1) Operating Procedures of CDPF
The most efficient and practical technology for now is adopted to the diesel particulate filter (DPF).
This system collects the soot from the diesel engine to the filter and burns the soot so that over than 95%
of soot can be removed from the exhaust gas. However, the durability and the cost of additional system
remainas problems.
Firstly, the exhaust gas is passed through the DOC and its temperature is increased as it is oxidized.
The ECU detects the temperature change with two temperature sensors. The CO, HC and partial
particulate material are removed from the exhaust gas (this procedures are the sames as the ones fo
r
the conventional DOC and no sensor is required).
After the exhaust gas is passed through the DOC and oxidized, most of the harmful material is removed
from the exhaust gas. However, to meet the environmental regulations in the future, the soot is filtered
and burnt again in DPF to decrease the particulate material further.
The filtered soot is burned whenever the vehicle is driven for 600 ~ 1200 km. The driving distance
can be differed depending on the
driving conditions. The soot is burnt for 15 ~ 20
minutes. -Exhaust
gas
Rear exhaust gas temperature
sensor(Measuring temperature of
exhaust gas escaping DOC)