Electronic control unit

In the 1999 Mercedes-Benz S-Class sedan, there are about 40 "electronic control units" that control up to 170 different variables. 

However, motor speed was also the first function in washing machines to be electronically controlled. The standard nowadays are controllable AC- or DC-mo-tors. Depending on the textile type or wash program, such drives can be used to achieve optimal wash speeds, reversing rhythms and activation times. Usually a tachogenerator on the motor is used as a speed sensor. Such a smaller modem motor, connected to a small electronic control unit, is shown on the right hand side of Fig. 3.2. 

Electronic components, gold, 12 699 Electronic conducting ceramics, 5 598-601 Electronic conduction, ceramics, 5 595-598 Electronic control unit (ECU)... 

In modem cars, microsensors play an essential and increasingly important role as the interface between the vehicle, with its complex functions of motor management, chassis systems, safety, as well as comfort and convenience on the one hand, and the respective electronic control units on the other hand. Microsensors need to function in a harsh environment over the entire lifetime of an automobile. Therefore reliability aspects have come more and more into the focus of engineering and research activities in microsystem technology. 

ACC differs from other vehicle control functions, especially in that the function is performed by several electronic control units (ECUs). While conventional control systems consist of a sensor and actuator environment around a central ECU, ACC adds functions to existing systems. A truly new component is the sensor for measuring the distance, relative speed, and lateral position of potential target vehicles, using laser optics or millimeter waves. This component often contains the logic for controlling vehicle movement. The latter is affected by commands of ECUs for engine and brake control electronics. 

Wheel-speed sensors do not monitor speed directly they sense the movement of the circumference of the tire. This is done with 48 or 32 pulses per turn, and some correction factor for tire sizes. This information comes from driven and non-driven wheels, and means four independent sources of information describing road surface, friction coefficient, cornering etc. In all cases the information is passed through the electronic control unit (ECU). ABS and all advanced systems are safety systems that do not allow the electrical signal to be split before it goes to the ECU. This is necessary to make a fail-safe system. 

The optical system used by most rain sensors consists of a light emitting diode (LED), a light receiving diode (LRD), an ambient light sensor, an electronic control unit (ECU), and several lenses (Fig. 7.14.2). 

Fig. 7.16.7 The smart NOx sensor made by NGK Insulators (left hand side) electronic control unit made by Sie-mensVDO Automotive (right hand side)...

The electronic control unit of a pressure-monitoring system consists of a microcontroller, data bus interface, and diagnostics. It evaluates the data it has received and transmits messages to the driver information system if necessary. 

The operating modes of the injectors are the following. When the electronic control unit (ECU) energizes the control valve solenoid, the control valve leaves its seat and the fuel pressure in the needle control chamber drops suddenly. As the fuel pressure at the nozzle seat is the same as the rail pressure, the needle opens and the injection starts. When the current in the solenoid valve is zero, the solenoid spring force returns the control valve to its seat [80]. 

The safety airbag alarm lamp flashes for 6 times and then extinguishes when the ignition switch is in ON position after the installation of new safety airbag system electronic control unit, which demonstrates the normal function of SRS safety airbag system. In this case the system does not need to be tested, otherwise it... 

Test condition Warning The test condition of this failure is the failure code that may not emerge before the test, DTC conducts the test, and the preparatory work must be done before the test because the damage to working personnel or system may be caused by the incorrect operation during the test. SRS safety airbag system electronic-control unit internal circuit failure. 

Low power-supply voltage for SRS safety airbag system electronic-control unit... 

Check the wiring harness between passengers side safety airbag module and SRS safety airbag system electronic-control unit Place the ignition switch in LOCK position Release accumulator negative wire and then wait for about 1 minute plus... 

Release all SRS safety airbag system unit connector clips Check whether the following troubles are with the circuit of the connector clips terminals between SRS safety airbag system electronic-control unit and passengers side safety airbag module Grounding... 

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