ECU SSANGYONG NEW REXTON 2012 User Guide

1533-01
Front temperature sensor
(Measuring the temperature of
exhaust gas passedthrough
exhaust manifold)Rear temperature sensor
(Measuring the temperature of exhaust
gas passed through DOC)
Differrential pressure sensor
(Front pressure port)Differrential pressure sensor
(Rear pressure port)
The engine ECU detects the
amount of particulate material
colected by the information
from temperature sensors
and differential pressure
snesor. When the soot is
accumulated, the pressure
difference be-tween the front
and the rear side occurs.
Then, the engineECU
performs the post injec-tion to
raise the exhaust gas
temperature and burn the
collected soot at approx. The exhaust gas enters
intoCDPF assembly after
passing through the exhaust
manifold. (Normal
temperature of ex-haust gas: When the exhaust gas
enters into the CDPF
assembly, its CO, HC and
particulate mate-rial are
reduced as it is oxi-dized in
DOC. The remaining
particulate material is
filtered and collected in
DPF and the temperature
of exhaust gas is increased

2) Fuel Injection During CDPF Regeneration
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 in-formed with this operation by an
y
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 tem-perature of the
exhaust gas. The driver may not feel any particular difference
from the vehicle.
No illumination

0000-00
Glow Plug
1. LAYOUT OF PRE-GLOW SYSTEM
The pre-glow system in D20DT engine has four glow plugs. And, the terminal T for pre-glow completion
signal is not used since the remote start function has been deleted.
Tightening torque
Engine ECUPre-glow Indicator
(Instrument cluster)
Ground
terminal
Pre-glow control
signal (ECU 113)IG1 power
terminal
Not available for the
vehicle without
remote start functionGlow plug
terminals
(#1~#4)
K-Line
(ECU 34)
G5 terminal
deleted
Battery
main
cable
Glow Plug Control Relay

0000-00
2. OPERATION
Glow plug is installed in the cylinder head. It enhances the cold starting performance and reduces the
exhaust gas during cold starting.
1. Pre-heating
2. Post-heating during engine running If normal communication with the ECU is established 2 seconds after the power is supplied to the IGN
terminal from the battery, the ECU supplies the battery voltage to glow plugs.
The post-heating controlled by ECU begins its operation after engine start The time for pre-heating is controlled by the ECU. -
The time for post-heating controlled by the ECU starts from engine start. This improves the idling
conditions and reduces the emission and noise. -
2) System Check
Glow Plug
Forced Shut-off of Relay
Check for short in each glow plug
Check for open due to over-voltage in each glow plug
Check for open to ground in glow plug -
-
-
When the glow plug circuit is open to ground. -
1) Operation
Pre-
heatingCoolant
temperature
Operating time 31s 22s 19s 17s 14s 0s 0s
Operating
conditions- IGN: ON
- B+: below 15.2 VStop
conditions- Time-out
- IGN: OFF
- when engine cranking
Post-
heatingCoolant
temperature
Operating time 115s 80s 30s 19s 11s 11s 0s
Operating
conditions- after engine start Stop
conditions-Time-out
- Torque: 190/170Nm
- rpm: 2100/2050

K-Line Communication
ECU starts to communicate by sending the result to pre-glow timer relay through K-Line.
Pre-glow timer relay sends the message with self-diagnosis data for glow plug to ECU.
The glow plug responses only for request.
ECU starts self-diagnosis operation from 2 seconds after power input.
Communication error occurs when: -
-
-
-
-
No response from pre-glow module for a certain period of time
Checksum error
Insufficient byte
3) DTC
DTC Description Error
P1678 GCU circuit is open GCU circuit is open
P1679 GCU circuit is short GCU circuit is short
P1680 GCU circuit is short to ground GCU circuit is short to ground
P1676Communication error Communication error between ECU and
GCU
P1677Defective GCU Communication error between ECU and
GCU
P0671 GCU channel 3 opened circuit GCU channel 3 circuit is open
P0672 GCU channel 4 opened circuit GCU channel 4 circuit is open
P0674 GCU channel 1 opened circuit GCU channel 1 circuit is open
P0675 GCU channel 2 opened circuit GCU channel 2 circuit is open

8510-23
2. CONFIGURATION
1) Circuit Diagram
The engine ECU detects the operating conditions of cruise control system, and monitors the braking
performance, vehicle speed, road conditions and ESP system operation. If the engine ECU determines
that there are not any problem to drive in cruise control mode, the vehicle can be operated by cruise
switch signals (decelerating, accelerating, cruising).

0000-00
4. GUIDELINES ON ENGINE SERVICE
To prevent personal injuries and vehicle damages that can be caused by mistakes during engine and
unit inspection/repair and to secure optimum engine performance and safety after service works, basic
cautions and service work guidelines that can be easily forgotten during engine service works are
described in.
Cautions before service works
For safe and correct works, you must observe the working procedures and instructions in this
manual. And, use the designated tools as follow:
Engine stand / Heavy duty engine jack
To prevent the engine from starting abruptly, do not allow anybody to get in the vehicle while
servicing in engine compartment.
Before work on engine and each electrical equipment, be sure to disconnect battery negative (-)
terminal.
Before service works, be sure to prepare the works by cleaning and aligning work areas.
Do not allow the foreign material get into the fuel injection system.
When removing the engine, use only the safety hook on engine and engine hanger. Do not support
the bottom of oil pan with a jack.
Engine and accessories
-
-
-
-
-
-
Completely drain the engine oil, coolant and fuel from engine before removal.
Before disassembling/assembling the engine components, carefully read the working procedures in
this manual.
Make sure to keep the specified tightening torques during installation.
Clean and properly lubricate the parts before reassembly.
Carefully check that there are not any interference while servicing. -
-
-
-
-

Brake booster and naster
cylinderVacuum pump
Pump capacity: 210 cc/rev
Camshaft speed: 375 to 3,000 rpm
Lubrication temperature: -40 to
Oil: 5W30
Drive type: Driven by exhaust
Camshaft sprocket
2. VACUUM PUMP
Vacuum pump generates the vacuum pressure and supplies it to EGR cooler bypass solenoid. This
pump is single vane type and displacement is 210 cc/rev. The lubrication oil is supplied through the hole
in hollow shaft.
Components
EGR cooler bypass valve
This valve is controlled by ECU.
When the engine is cooled, the
exhaust gas goes to combustion
chamber without passing through
EGR cooler because the valve is
closed by vacuum pressure.

2210-01
2) Cleanness
(1) Cleanness of DI engine fuel system
Cleanness of DI engine fuel system and service procedures
The fuel system for DI engine consists of transfer (low pressure) line and high pressure line.
Its highest pressure reaches over 1,800 bar.
preciseness.
The pressure regulation and injector operation are done by electric source from engine ECU.
Accordingly, if the internal valve is stuck due to foreign materials, injector remains open.
Even in this case, the HP pump still operates to supply high pressurized fuel. This increases the
pressure to combustion chamber (over 250 bar) and may cause fatal damage to engine.
You can compare the thickness of injector nozzle hole and hair as shown in below figure (left side). The
below figure shows the clearance between internal operating elements.
The core elements of fuel system has very high preciseness that is easily affected by dust or very small
foreign material. Therefore, make sure to keep the preliminary works and job procedures in next pages.
If not, lots of system problems and claims may arise.
Hair
Nozzle holeValve actuator lift - 0.028 mm
Diameter
0.04 mm
Operating
clearance
0.002 mm
Diameter
2.0 mm

(2) Di engine and its expected problems and remedies can be caused by
water in fuel
System supplement against paraffin separation
In case of Diesel fuel, paraffin, one of the elements, can be separated from fuel during winter and then
can stick on the fuel filter blocking fuel flow and causing difficult starting finally. Oil companies supply
summer fuel and winter fuel by differentiating mixing ratio of kerosene and other elements by region and
season. However, above phenomenon can be happened if stations have poor facilities or sell improper
fuel for the season. In case of DI engine, purity of fuel is very important factor to keep internal
preciseness of HP pump and injector.
Accordingly, more dense mesh than conventional fuel filter is used. To prevent fuel filter internal clogging
due to paraffin separation, SYMC is using fuel line that high pressure and temperature fuel injected by
injector returns through fuel filter to have an effect of built-in heater (see fuel system).
System supplement and remedy against water in fuel
As mentioned above, some gas stations supply fuel with excessive than specified water. In the
conventional IDI engine, excessive water in the fuel only causes dropping engine power or engine
hunting. However, fuel system in the DI engine consists of precise components so water in the fuel can
cause malfunctions of HP pump due to poor lubrication of pump caused by poor coating film during high
speed pumping and bacterization (under long period parking). To prevent problems can be caused by
excessive water in fuel, water separator is installed inside of fuel filter. When fuel is passing filter, water
that has relatively bigger specific gravity is accumulated on the bottom of the filter.
Water drain from water separator
If water in the separator on the fuel filter exceeds a certain level, it will be supplied to HP pump with fuel,
so the engine ECU turns on warning lamp on the meter cluster and buzzer if water level is higher than a
certain level.
Due to engine layout, a customer cannot easily drain water from fuel filter directly, so if a customer
checks in to change engine oil, be sure to perform water drain from fuel filter.
Water
separator
To separate the water from the fuel filter,
remove the fuel filter assembly first.