Fuel-consumption signal
The engine ECU (Fig. 1, Pos. 3) detects the engine fuel consumption and transmits the signal via CAN to the instrument cluster, or to an independent on-board computer (6), where the driver is informed of the current fuel consumption and/or the remaining range with the fuel still in the tank. Older systems used pulse-width modulation (pwm) for the fuel-consumption signal. Starter control
The starter (8) can be triggered from the en- gine ECU. This ensures that the driver can- not operate the starter with the engine al- ready running. The starter only turns long enough for the engine to have reliably reached self-sustaining speed. This function leads to a lighter and thus lower-priced starter.
Glow control unit
The glow control unit (GZS, 5) receives in- formation from the engine ECU on when glow is to start and for how long. It then triggers the glow plugs accordingly and monitors the glow process, as well as report- ing back to the ECU on any faults (diagnosis function). The pre-glow indicator lamp is usually triggered from the ECU.
Electronic immobilizer
To prevent unauthorized starting and drive- off, the engine cannot be started before a special immobilizer (7) ECU removes the block from the engine ECU.
Either by remote control or by means of the glow-plug and starter switch (“Ignition” key), the driver can signal the immobilizer ECU that he/she is authorised to use the ve- hicle. The immobilizer ECU then removes the block on the engine ECU so that engine start and normal operation become possible.
46 Open and closed-loop electronic control Data exchange with other systems
Figure 1 1 ESP ECU
(with ABS and TCS) 2 ECU for transmis-
sion-shift control 3 Engine ECU (EDC) 4 A/C ECU 5 Glow control unit 6 Instrument cluster with on-board com- puter 7 Immobilizer ECU 8 Starter 9 Alternator 10 A/C compressor 1 2 3 4 9 5 6 7 8 10
Possible components involved in the exchange of data with the Electronic Diesel Control (EDC) 1
æ
U AE0 7 7 7YExternal torque intervention
In the case of external torque intervention, the injected fuel quantity is influenced by another (external) ECU (for instance the ECU for transmission shift, or for TCS). This informs the engine ECU whether the engine torque is to be changed, and if so, by how much (this defines the injected fuel quantity).
Alternator control
By means of a standard serial interface, the EDC can remotely control and remotely monitor the alternator (9). The regulator voltage can be controlled, just the same as the complete alternator assembly can be switched off. In case of a weak battery for in- stance, the alternator’s charging characteris- tic can be improved by increasing the idle speed. It is also possible to perform simple alternator diagnosis through this interface.
Air conditioner
In order to maintain comfortable tempera- tures inside the vehicle when it is very hot outside, the air conditioner (A/C) cools down the air with the help of a refrigerating compressor (10). Depending upon the en- gine and the operating conditions, the A/C compressor can need as much as 30% of the engine’s output power.
Immediately the driver hits the accelerator pedal (in other words he/she wishes maxi- mum torque), the compressor can be switched off briefly by the engine ECU, so that all the engine’s power is available at the wheels. Since the compressor is only switched off very briefly, this has no notice- able effect upon the passenger-compartment temperature.
Open and closed-loop electronic control Data exchange with other systems 47
Where does the word “Electronics” come from?
This term really originates from the ancient Greeks. They used the word electron for "am- ber" whose forces of attraction for wool and similar materials had already been described by Thales von Milet 2,500 years ago.
The term “electronics” originates directly from the word “electrons”. The electrons, and therefore electronics as such, are extremely fast due to their very small mass and their electrical charge.
The mass of an electron has as little effect on a gram of any given substance as a 5 gram weight has on the total mass of our earth.
Incidentally, the word “electronics” is a prod- uct of the 20th century. There is no evidence available as to when the word was used for the first time. Sir John Ambrose Fleming, one of the inventors of the electron tube could have used it around 1902.
The first “Electronic Engineer” though goes back to the 19th century. He was listed in the 1888 Edition of a form of “Who’s Who”, pub- lished during the reign of Queen Victoria. The official title was “Kelly’s Handbook of Titled, Landed and Official Classes”. The Electronic Engineer is to be found under the heading “Royal Warrant Holders”, that is the list of per- sons who had been awarded a Royal Warrant.
And what was this Electronic Engineer’s job? He was responsible for the correct func- tiong and cleanliness of the gas lamps at court. And why did he have such a splendid ti- tle ? Because he knew that “Electrons” in an- cient Greece stood for glitter, shine, and sparkle.
Source:
“Basic Electronic Terms” (“Grundbegriffe der Elektronik”) – Bosch publication (reprint from the “Bosch Zünder” (Bosch Company News- paper))..