CHAPTER 2: ELECTRONIC SYSTEMS

2.1.1 Electronic Ignition Systems For complete combustion, the ignition system must supply properly timed, high-voltage surges across each pair of spark plug electrodes at the proper time under all engine operating conditions. Purpose of Ignition System are: It must generate an electrical spark with enough heat to ignite the air-fuel mixture in the combustion chamber. It must maintain that spark long enough to allow total combustion of the fuel in the chamber. It must deliver the spark to each cylinder to allow combustion to begin at the right time during the compression stroke. There are basically two types of ignition systems: distributor ignition (DI) and electronic ignition (EI) or distributorless ignition systems (DIS)  Distributor ignition (DI) is the term specified by the Society of Automotive Engineers (SAE) for an ignition system that uses a distributor.  Electronic ignition (EI) is the term specified by the Society of Auto...

2.2.1 Airbags An airbag is a vehicle occupant restraint system using a bag designed to inflate extremely rapidly then quickly deflate during a collision. It consists of the airbag cushion, a flexible fabric bag, inflation module and impact sensor. The purpose of the airbag is to provide the occupants a soft cushioning and restraint during a crash event. It can reduce injuries between the flailing occupant and the interior of the vehicle. The airbag provides an energy absorbing surface between the vehicle's occupants and a steering wheel, instrument panel, as well as the body pillars, headliner, and windshield. Modern vehicles may contain multiple airbag modules in various configurations including, driver, passenger, side curtain, seat-mounted side impact, knee bolster, inflatable seat-belt, front right and left side sensors and pedestrian airbag modules. During a crash, the vehicle's crash sensors provide crucial information to the airbag electronic controller uni...

2.3.1 Integrated Communications Modern vehicles integrate audio, video and communication systems into a network.  This allows for a high quality, compact and ergonomic system, which combines entertainment features with simple operation. Controls are centralized with hardware, such as CD stackers, and DVD players located remotely. Communication between components uses a combination of hard wiring and data buses. With data buses being used, audio messages can be broadcast over the audio system that relate to other vehicle systems. For example, a voice message can say “the park brake is on” or “left rear tire is under inflated”. The system allows for features such as the interruption or replacement of audio entertainment when there is an incoming phone call, or simply muting the audio to allow a hands-free phone conversation. Audio control functions are usually located on the central control pod or on the component’s head unit. Vehicles can integrate the common audio contr...

2.4.1 Triangulation vs Trilateration Trilateration Measures Distance, Not Angles How does the GPS system pinpoint your location using trilateration? Using a simple two-dimensional example, let’s imagine we have three GPS satellites each with a known position in space. Really, all that satellites do is broadcast a signal for your GPS receiver to pick up with a specific time and distance. For example, the first satellite broadcasts a signal that eventually hits your GPS receiver. We don’t know the angle, but we do know the distance. That’s why this distance forms a circle equal in all directions. This means that your GPS position could be anywhere on this circle at this specific radius. What happens when your GPS receives a second signal? Again, this distance is equally broadcasted in all directions until it hits your GPS receiver. This means that the distance could be anywhere on that circle. But this time, we have two known distances from two satellites. With...