SsangYong Korando III (2010 year). Manual — part 71

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2. SYSTEM OPERATION

1) Input/Output of ECU

(1) ECU Block diagram

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Fuel rail

pres.sensor

Differential

pressure

sensor

Swirl valve posi.

sensor

Meter cluster

Coolant temp.

sensor

E-EGR valve

posi. sensor

Oxygen

sensor

Exhaust gas

temp. sensor

HFM sensor

(2) Components for ECU Input

Crankshaft posi.

sensor

Accel. pedal

posi. sensor

Throttle

posi.sensor

Knock sensor

T-MAP sensor

Camshaft posi.

sensor

CAN

- ABS&ESP
- GCU
- Meter cluster
- TCU
- BCM

- Refrigerant pressure sensor
- Clutch pedal signal
- Blower switch signal
- Brake pedal signal

Oil level sensor

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Engine room

relay box

E-EGR valve

Cooling fan

E-EGR cooler

bypass valve

E-VGT

actuator

IMV

Throttle posi.

sensor

Injector

A/C

compressor

Start motor

Variable swirl

valve

(3) Components for ECU Input

PTC heater

CAN

- Glow plug unit
- ABS & ESP unit
- BCM
- E-coupling unit
- EPS
- GCU
- Meter cluster
- SKM
- TCU
- Self diagnosis

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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.
Operating temperature range of ECU is normally -40 to +85°C and 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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