Electrical Wiring Diagrams C. CIRCUIT DESCRIPTION INPUT SIGNAL OF ECU

/library/BOOKS/CAR/SsangYong/Actyon/Actyon_EWD_C0105003.pdf\n5- Electrical Wiring Diagrams
C. CIRCUIT DESCRIPTION
INPUT SIGNAL OF ECU
According to input signals from various sensors, engine ECU calculates driver’s demand (position of the acceleratorpedal)
and then controls overall operating performance of engine and vehicle on that time. ECU receives signals from sensors
through data line and then performs effective engine air-fuel ratio controls based onthose signals.
Engine speed is measured by crankshaft speed (position) sensor and camshaft speed (position) sensor
determinesinjection order and ECU detects driver’s pedal position (driver’s demand) through electrical signal that
generated byvariable resistance changes in accelerator pedal sensor.
Air flow (hot film) sensor detects intake air volume and then transmits to ECU. Especially, the engine ECU
controls theair-fuel ratio by recognizing instant air volume changes through air flow sensor to pursue low emission
gases (EGR valvecontrol). Furthermore, the ECU uses signals from coolant temperature and air temperature
sensor, booster pressuresensor and atmospheric pressure sensor as compensation signal to respond to injection
start and pilot injection setvalues and to various operations and variables.
CONTROL FUNCTION OF ECU
1. Controls by operating stages:
To make optimum combustion under every operating stage, ECU should calculate proper injection volume
ineach stage by considering various factors.
2. Starting injection volume control:
During initial starting, injecting fuel volume will be calculated by function of temperature and engine
crankingspeed.
Starting injection continues from when the ignition switch is turned to ignition position to till the engine
reachesto allowable minimum speed.
3. Driving mode control:
If the vehicle runs normally, fuel injection volume will be calculated by accelerator pedal travel and engine
rpmand the drive map will be used to match the drivers inputs with optimum engine power.
ECU INPUTS·OUTPUTS
Inputs Control Outputs
Booster pressure sensor
Atmospheric pressure sensor Injector
(Built-in ECU) EGR system
Air flow sensor (HFM) Fuel pressure regulating valve (IMV)
Coolant temperature sensor Electrical fan control (Low/High-speed)
Fuel temperature sensor E A/C compressor relay
Fuel pressure sensor Glow plug relay
Fuel filter water sensor Immobilizer
Knock sensor C Warning lights
crankshaft position sensor (Water warning light, glow plug indica-
camshaft position sensor
Accelerator sensor
U tor light, engine warning light)
Preheater (auxiliary heater)
Vehicle speed sensor K - line
Switch input signal CAN communication
(IG, brake, clutch, A/C signal, A/C Self-diagnosis
compressor)
Electrical Wiring Diagram (LHD)