The document discusses the purpose and function of onboard automotive computers. It explains that computers receive input from various sensors, process the data, store it in memory, and send output signals to control devices. It then lists common computer components like the CPU and memory. It describes how computers use switches, pulse-width modulation, and digital signals to control devices like fuel injectors and ignition timing.

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17. Figure 53–5 A typical low-side driver (LSD) which uses a control module to control the ground side of the relay coil. Continued

19. Figure 53–6 A typical module-controlled high-side driver (HSD) where the module itself supplies the electrical power to the device. The logic circuit inside the module can detect circuit faults including continuity of the circuit and if there is a short-to-ground in the circuit being controlled. Continued

21. Figure 53–7 Both the top and bottom pattern have the same frequency. However, the amount of on-time varies. Duty cycle is the percentage of the time during a cycle that the signal is turned on. Continued

41. Figure 53–15 A ring link network reduces the number of wires it takes to interconnect all of the modules. See the chart on Page 612 of your textbook. Continued

43. Figure 53–16 A star-link-type network where all of the modules are connected together using splice packs. See the chart on Page 613 of your textbook.

49. A bus is a term used to describe a communication network. Therefore, there are connections to the bus and bus communications, both of which refer to digital messages being transmitted among electronic modules or computers. What is a Bus?

51. Figure 53–18 Checking the terminating resistors using an ohmmeter at the DLC.

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