Page 1233 - Foton Workshop Manual - Tunland (AT)

ENGINE CONTROL SYSTEM - ENGINE CONTROL SYSTEM 11-7

7 . Postprecessing preheating oxidation catalyst 11
The function of postprecessing preheating oxidation catalyst is to convert the hazardous
emission of the engine combustion into harmless gas before discharging it into the air.
The internal structure of postprecessing preheating oxidation catalyst is designed as
honeycomb-like pipes. Pd, Rh, Pt and other noble metals are coated over the
honeycomb pipe wall, serving as catalyst. Postprecessing preheating oxidation catalyst
reduces 3%-5% of the engine power.

8 . Postprecessing preheating oxidation catalytic overheat system protection
function
According to the actual working condition of the engine, the system forecasts the
increase of engine emission temperature and reduces the engine combustion
temperature by properly controlling the mixture ration of fuel and air, so as to protect
the postprecessing preheating oxidation catalytic.
9 . Radiator fan control
(a) The vehicle is equipped with an electric dual-speed engine cooling fan and an A/C
condenser fan.
(b) Electric fan control: Depending on the engine coolant temperature and whether it
meets the condition to turn on the A/C, ECM determines whether to turn on the fans
in order to reduce the internal engine power consumption.
10 . Injection timing control
The basic starting time of fuel injection is calculated by the fuel injection and engine
speed, then the injection starting timing is corrected by inlet temperature, coolant
temperature and atmospheric pressure.

11 . Fuel injection pressure control
At starting, the fuel injection pressure is calculated by engine speed, fuel injection,
and coolant temperature. In normal condition, the fuel injection pressure is calculated
by engine speed and fuel injection. When starting, if the water temperature is low, the
injection pressure is raised.
12 . Altitude compensation

As the altitude rises, the atmospheric pressure drops. This makes the cylinder to be
filled with less air, which means that the fuel injection must be reduced accordingly,
otherwise excessive soot will be generated. In order to correct the injection volume at
high altitude, ECM measure the change of atmospheric pressure by an atmospheric
pressure sensor. According to the measured atmospheric pressure signal, ECM
modifies the fuel injection according to the changing factors of atmospheric pressure.
Atmospheric pressure also affects pressurization pressure control and torque limitations.
13 . Cruise control
Cruise control allows the vehicle to be driven at a constant speed. The driver can set
the required speed by manipulating a handle or press the steering wheel button. At
this time, without stepping on the accelerator pedal, ECM directly control the fuel
injection increase or decrease to reach the hope (set) speed.

14 . Active surge decrease

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