SYSTEM / Controller ECM: ENGINE CONTROL MODULE Function Outline ECM (Engine Control Module) receives the signals from sensors and MC ECM processes and drives the two-way valve, suc- tion control valve and EGR (Exhaust Gas Recircula- tion) motor in order to control the supply pump, in- jector pump and EGR valve. ECM has the controls as follows. Fuel Injection Control ECM detects the engine operating condition ac- cording to the signals from each sensor and MC and controls the fuel injection. Fuel Injection Amount Correction ECM adjusts fuel injection amount according to the signal of atmospheric pressure sensor.
Preheating Control ECM controls time for continuity of electrical cur- rent for the glow plug according to coolant tem- perature and improves the starting of engine. EGR Control ECM decides EGR gas amount according to en- gine speed, fuel flow rate, coolant temperature, atmospheric pressure and intake-air temperature. ECM opens EGR valve and re-circulates exhaust gas, amount of which is equal to EGR gas amount, in the intake manifold. EGR gas is combined with intake-air so that combustion temperature is low- ered and NOx is reduced. Engine Stop Control When the emergency stop switch is turned to the ON position, ECM stops the fuel injection of in- jector and stops the engine. NOTE:
As for details on each control, refer to the ECM System group / SYSTEM. T2-1-12