2012 SSANGYONG NEW REXTON brake

0000-00
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.
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. -
-
-

A fourth correction is made according to the pressure error.
This correction is used to reduce the injection timing advance when the pressure in the rail is higher
than the pressure demand.
A fifth correction is made according to the rate of EGR.
This correction is used to correct the injection timing advance as a function of the rate of exhaust gas
recirculation. -
-
<003a004b0048005100030057004b004800030028002a0035000300550044005700480003004c00510046005500480044005600480056000f00030057004b00480003004c0051004d004800460057004c0052005100030057004c0050004c0051004a000300
44004700590044005100460048000300500058005600570003[in fact be increased in order to
compensate for the fall in termperature in the cylinder.
A. Main Flow Control
The main flow represents the amount of fuel injected into the cylinder during the main injection. The pilot
flow represents the amount of fuel injected during the pilot injection.
The total fuel injected during 1 cycle (main flow + pilot flow) is determined in the following manner.
When the driver depress the pedal, it is his demand which is taken into account by the system in order
to determine the fuel injected.
When the driver release the pedal, the idle speed controller takes over to determine the minimum fuel
which must be injected into the cylinder to prevent the enigne from stalling. -
-
It is therefore the greater of these 2 values which is retained by the system. This value is then compared
with the lower flow limit determined by the ESP system.
As soon as the injected fuel becomes lower than the flow limit determined by the ESP system, the
antagonistic torque (engine brake) transmitted to the drive wheels exceeds the adherence capacity of
the vehicle and there is therefore a risk of the drive wheels locking.
The system thus chooses the greater of these 2 values (main flow & pilot flow) in order to prevent any
loss of control of the vehicle during a sharp deceleration.
As soon as the injected fuel becomes higher than the fuel limit determined by the ASR trajectory control
system, the engine torque transmitted to the wheels exceeds the adhesion capacity of the vehicle and
there is a risk of the drive wheels skidding. The system therefore chooses the smaller of the two values
in order to avoid any loss of control of the vehicle during accelerations.
The anti-oscillation strategy makes it possible to compensate for fluctuations in engine speed during
transient conditions. This strategy leads to a fuel correction which is added to the total fuel of each
cylinder.
A switch makes it possible to change over from the supercharge fuel to the total fuel according to the
state of the engine.
Until the stating phase has finished, the system uses the supercharged fuel.
Once the engine changes to normal operation, the system uses the total fuel. -
-
(5) Fuel Control
The main fuel is obtained by subtracting the pilot injection fuel from the total fuel.
A mapping determines the minimum fuel which can control an injector as a function of the rail pressure.
As soon as the main fuel falls below this value, the fuel demand changes to 0 because in any case the
injector is not capable of injecting the quantity demand.

2) Cautions on Service Procedures
Before lifting up the vehicle with a lift, correctly support the lifting points.
When using a jack, park the vehicle on a level ground and place the wheel chocks under the
tires. Position the jack under the frame and lift up the vehicle and then support with chassis
stand before service work.
Make sure to disconnect the negative (-) cable from the battery to prevent any damage to
electric systems.
If you have to work on vehicle, cover the seats and floor with protection covers to avoid any
damage and contamination.
Brake fluid and anti-freeze can damage the painted surface of body. So carefully handle them
during service work.
To improve the efficiency of service work, use only recommended and specified tools.
Use only Ssangyong genuine spare parts.
Never reuse the cotter pin, gasket, O-ring, oil seal, lock washer and self-locking nut. Replace
them with new ones. If reused, normal functions cannot be maintained.
Store the disassembled parts as a set based on disassembly order and unit.
Pay particular attention not to miss or mix the fasteners.
If necessary, especially for inspection, clean the removed parts completely.
Apply the oil or grease on the running and sliding surfaces before installation. Use the specified
sealant and gasket to prevent leakage if necessary.
Tighten the fasteners with the specified tightening torque.
As a final stage of service work, check if the serviced system is working properly and the
problem has been eliminated clearly. 1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.

Engine Compartment Layout
Engine assembly
Engine oil dipstick
Vacuum pump
Oil filter and cooler
Fuel filter and priming pump
Brake booster
Brake oil tank
AQGS unit
Washer fluid filler cap
Engine compartment fuse box
PTC relay box
Battery
Vacuum modulator (for VGT turbo charger) 1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.FFH Assembly (Only for vehicle with FFH)
Power steering oil tank
Engine oil filler cap
Fan shroud
E-EGR Valve
High-capacity PCV oil separator
HFM sensor (6.0)
VGT turbo charger
Air cleaner housing
2Coolant surge tank
ABS/ESP HECU (Including TPMS function:
optional)
Exhaust gas FRT Temp. sensor (T3) 14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.

1212-01
1. D27DT ENGINE STRUCTURE
1) Major Components in Engine and Engine Compartment
The advanced electronically controlled D27DT engine that has high pressure fuel system has
been introduced to this vehicle. It satisfies the strict emission regulation and provides improved
output and maximum torque.
1. Coolant reservoir
2. FFH device
3. Brake fluid reservoir
4. Washer fluid reservoir
5. Common rail6. Fuse box
7. Battery
8. Fuel filter
9. Power steering pump
10. Priming pump11. EGR valve
12. Air cleaner assembly
13. Turbo charger
14. Oil dipstick

8510-23
3) Decelerating with the Cruise Control System
(1) While the cruise control system is running
Push down the DECEL switch of the cruise control lever and hold it until the desired speed is
reached without a brake pedal intervention. But the cruise control system cannot maintain the
cruise function at less than 34 km/h.
When the desired speed is reached, release the lever. 1.
2.
(2) When the cruise control system is not running
To decrease the vehicle speed with the cruise control system when the system is not running,
follow the procedures below.
Push down the cruise control switch lever to DECEL side and hold it until the desired speed is
reached while the vehicle speed is over 36 km/h.
And then release the accelerator pedal slowly.
When the desired speed is reached, release the lever. But the cruise control system cannot
maintain the cruise function at less than 34 km/h. 1.
2.
3.
(3) Tap-down while the cruise control system is running
To decrease the vehicle speed in stages while the cruise control system is running, follow the
procedures below.
Push down the DECEL switch of the cruise control lever less than 0.5 second per one switching
while the cruise control system is running. This is a tap-down switching. When you operate a
tap-down switching, the vehicle is decelerated for 1.0 km/h below the previous set speed.
If you want to decelerate for 10 km/h, operate the tap-down switching ten times without the
brake pedal intervention. 1.
2.

4) Recovery of Set Speed (RESUME)
Even if the cruise control is cancelled, the previous set cruise speed can be recovered by pulling
up the cruise control lever when the current vehicle speed is over 36 km/h without an acceleration
intervention. But if you turn off the ignition switch, the memorized set speed is cleared and you
cannot recover the previous set speed.
But the driver should know the previous set speed to react to the changed vehicle speed
properly. If the vehicle speed increases abruptly, depress the brake pedal to adjust the vehicle
speed properly.

8510-23
5) Normal Cancellation of the Cruise Control
The cruise control system will be canceled when one or more items of the following conditions
are applied;
When the brake pedal is depressed or When ESP is activated.
When the cruising speed is downed less than 34 km/h
When applying the parking brake during driving.
When using the clutch in order to shift (M/T only). 1.
2.
3.
4.
Keep the main cruise control switch in the neutral position when not using the cruise control.