Page 2574 - Foton Workshop Manual - Sauvana

62-522 DIAGNOSIS-ENGINE CONTROL SYSTEM

pump, crankshaft rotation can be used to slow down the vehicle When the engine
is in reverse towing or towing conditions, the fuel injection is cut to reduce fuel
consumption and exhaust emissions, more importantly, to protect the three-way
catalytic converter. Once the speed is reduced to a particular speed of restoring
the fuel supply above the idle speed, the injection system is refueled.
• When the injection system is refueled, the system begins to supply the supplemental
fuel with the primary injection pulse and reconstructs the oil film on the intake
manifold wall. After the restoration of fuel injection, the engine torque is increased
slowly and smoothly in the torque-based control system ( smooth transition )
(f). Knock Control .
• The system installs the knocking sensor between the two cylinders and three
cylinder of engine to detect the characteristic vibration in the knocking and convert
the characteristic vibration into electronic signals for transmission to the ECU and
processing
• ECU uses a special processing algorithm to detect whether knocking occurs in
each combustion cycle of each cylinder. Knocking closed loop should be triggered
when the knocking is detected. When the knocking hazard is eliminated, the
affected cylinder is gradually re-advanced to the predetermined ignition advance
angle.
(g). Over voltage protection .
• When the charging system failure causes the high voltage, the system will enter
the protection state and limit the engine speed to avoid the damage of .ECU .
(h). Air conditioning compressor control .
• When the air conditioning switch is turned on, the system will receive a signal
called the air conditioning request and make preparation for loading air
conditioning according to the working conditions of the engine at present, then
connecting to the air conditioning compressor.
• System will switch on or off the air-conditioning according to the protection
demand of air-conditioning itself. In order to ensure the power output and protect
the engine, the system will cut off air-conditioning under certain conditions.
(i). Evaporative emission control .
•·The fuel in the fuel tank will be heated because of the transmission of external
radiant heat and return oil heat and forms the fuel vapor.
•·The vapor containing large amounts of HC is not allowed to be discharged
directly into the atmosphere due to the limitations of evaporative emission
regulations. In the system, the fuel vapor is collected in the charcoal canister
through the conduit and enters the engine by flushing, participate in the
combustion process at the appropriate time.
•·The flow of the purge stream is determined by controlling the carbon canister
control valve with ECU . This control takes effect when the closed loop control
system is in the status of closed loop.
(j). Radiator fan control.
• The vehicle is equipped with electric two-speed engine cooling fan.
• The control function of electric fan: ECH determines to switch on each fan

Page 2574