
Control mode of ignition advance angle is normally an open loop control. However, this open loop control is not the same
as common open loop control. While ECU controls in open loop mode and outputs command of ignition advance angle, it
also monitors knocking signal from time to time through the knocking sensor. Once knocking occurs, control will be
transferred into closed loop mode immediately. Its feedback signal is the signal of knocking sensor. Therefore it is also a
closed loop control on the whole.
ECU unit: electronic control unit to receive various information from sensors. After processing and analysis, it sends
control impulse to individual actuator, serving as nerve center in the electronic control system.
Hardware of electronic control unit (ECU) can be divided into three parts, i.e. input stage,
microcomputer and output stage (see Fig. 365).
Section 2 System Composition and Working Principle
Fig. 365 Hardware Composition of Electronic Control Unit
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Summary of Contents for JL481Q
Page 1: ......
Page 9: ...5 Fig 3 Components Assembly Drawing of MR479Q MR479QA Engine ...
Page 10: ...6 Fig 4 MR479Q MR479QA Engine and Its Power System ...
Page 11: ...7 Fig 5 Assembly Drawing of Engine and Its Auxiliaries MR479Q MR479QA ...
Page 12: ...8 Fig 6 Electronic Control Fuel Injection System in Engine MR479Q MR479QA ...
Page 13: ...9 Fig 7 Front view of Engine JL481Q MR481QA ...
Page 14: ...10 Fig 8 Sectional elevation of Engine JL481Q MR481QA ...
Page 15: ...11 Fig 9 Electronic Control Fuel Injection System in Engine JL481Q MR481QA ...