7. Vehicle Components

Traditionally, a vehicle had 8 "systems" that made up the basics of the vehicle. Lately, a ninth system, the "SUPPORT SYSTEM" has been added, due to the complexities of computerization and crash-safety.

Several of these systems are important to you, the driver, for the safe operation of your vehicle, and state law requires that you have a "working knowledge" of them.

The following pages will show some of the basics of these systems.

The purpose of a vehicle’s frame is to support the body, engine, and other components.

The frame along with the body is largely responsible for the structural integrity of the vehicle. The frame itself is supported by the wheels and tires through the vehicle’s suspension system.

Most newer cars, and some vans and light trucks, use a unibody design, where the body and frame are all one unit.

This short movie will give you a brief overview of the 4-stroke engine that is used by most vehicles.

Also called the "Otto" cycle engine, for its designer, it is a relatively efficient engine, converting the energy of exploding gasoline into mechanical energy to propel the vehicle.

When you start your car:

The moving parts of your engine must be lubricated. Oil which accumulates in your engine's oil pan is pumped by the oil pump through an oil filter and then through tubes that deliver the oil to the moving parts that need to be lubricated.

Fuel and air is delivered to the engine through components which include:

The transmission is a gear-reduction machine that takes the output of the engine and changes it, through different gear ratios, into either "high-torque-low-speed" or "low-torque-high-speed" output to the wheels.

The transmission can be MANUAL shift, in which case the driver changes the gear ratio by using a "shifter" or "gear selector"; or it can be an AUTOMATIC shift, where hydraulic fluid and pressure valves are used to change the gear ratios.

In either case, the output power is transmitted to a DRIVE SHAFT, or in the case of front-wheel drive, to two HALF-SHAFTS, which then deliver the power to the wheels.

Between the transmission and the drive shaft is a DIFFERENTIAL, a series of gears that allows for the left and right wheels to turn at different speeds while still applying power.

A vehicle's power train consists of components that generate and transmit power to the wheels.

In a rear-wheel drive vehicle, the power train includes:

In a front-wheel drive vehicle, the power is transmitted from the engine through a combination transmission-differential and then directly to the front wheels.

In a four-wheel drive vehicle, the power is transmitted from the transmission to a transfer case which can transmit power to either the rear wheels only or to both the rear and front wheels.

The steering system includes the steering wheel and all of the links between it and the wheels. On older cars, and on light trucks, a system of links called "parallelogram linkage" is connected to a gear box, which changes the rotary motion of the steering wheel to linear movement of the linkage to cause the wheels to change position from straight ahead.

A vehicle's steering wheel is attached to a steering column or shaft which terminates in the steering box . Inside the steering box, the turning motion of the column is translated into a lateral motion which is passed on to the wheels through a series of components which include ball joints , the steering arm , and the steering knuckle .

When you turn the steering wheel in a power steering system you cause hydraulic fluid to be compressed inside a hydraulic cylinder and transmitted by hydraulic lines to a piston which amplifies the force making it easier to turn the wheels. In order for the hydraulic system to operate, the engine must be running.

Most vehicles today use a system called " Rack and Pinion " steering, where the steering wheel and the steering wheel shaft is directly connected to a toothed rod which directly turns the wheels.

The purpose of your vehicle's suspension system is to:

The up and down movement of your wheels is absorbed by the springs in your suspension system, your shock absorbers keep the springs from continuing to bounce, and there are different designs for suspension systems involving various linkages, struts, joints, torsion bars, and so on.

Your battery is the vehicle's primary source of electrical power when the car is off.

When you turn your ignition switch to start your car electricity is used to close another switch called a solenoid that transmits the large amount of current needed to turn the starter motor.

Once your engine is running, power is generated by the alternator which also keeps your battery charged.

Your voltage regulator controls the amount of electricity that is generated.

Your distributor and coil generate and deliver the very high voltage electricity needed by the individual spark plugs of your engine

Electricity is distributed throughout your vehicle by various electrical circuits for lighting, to operate electrical motors, to operate computers that control various functions, to operate your radio, interior cooling, heating, and ventilating system.

The purpose of fuses is to disable a circuit that is drawing too much current so as to prevent a fire and protect the components that the circuit serves.

The ignition system delivers voltage to ignite the fuel in the automotive vehicle. When the ignition switch is turned on, low-voltage electric current flows from the battery to the coil, which converts the current to high-voltage. The current then flows to the distributor, which delivers it to each of the spark plugs. The spark plugs send an igniting spark to the fuel/air mixture in the combustion chambers.

The lighting system is a dual-purpose system; it is for safety (allowing you to "see" in the dark, and for others to see you) and for communicating to others (turn signals, emergency flashers, brake lights).

The heat caused by the friction of moving engine parts and the explosion of gasoline in the cylinders is removed through the vehicle's cooling system. In this system:

Antifreeze is considered by many to be "one-size-fits-all" as most antifreeze brands have a distinctive lemon-lime color. However, the actual formulations can vary greatly between types, such as the new RED antifreeze. Conventional antifreeze is formulated from an ethylene glycol (EG) base chemical and can have very serious health risks.

It is estimated that each year 90,000 pets and other wildlife die from accidentally ingesting ethylene glycol based antifreeze. Animals are attracted to antifreeze for its sweet smell and taste. Animals, and children for that matter, can accidentally ingest antifreeze from spills, cooling-system leaks or improperly stored containers. Because of this the U.S. Government has initiated strict laws and penalties as the result of contamination of water or ground areas. Even a leaky vehicle can get you into trouble.

As an alternative, automotive chemical manufacturers have formulated a newer type of antifreeze using propylene glycol (PG) instead of ethylene glycol, which is less harmful if accidentally ingested. A popular brand is SIERRA® , which was the first nationally marketed propylene glycol based antifreeze.

Safer, propylene glycol based antifreeze provides performance and protection comparable to conventional ethylene glycol based antifreeze in four key areas of engine protection: boil over, freeze-up, corrosion and heat transfer. SIERRA®, and other propylene glycol based antifreeze products are available nationwide, and can be the extra margin of safety to protect your children, pets, drinking water, and neighborhood wildlife.

There are two independent braking systems in your vehicle, the service brakes and the parking brake (also referred to as the emergency brake ). The service brakes are used to slow your vehicle while you are driving. The parking brake can also be used to slow your vehicle in an emergency , but is mainly used to hold your vehicle in one place while stopped or parked.

When you press your brake pedal, a piston in your master cylinder forces brake fluid through hydraulic lines to pistons in the wheel cylinders at the wheels where additional pistons provide the force to apply your brakes. Hydraulic fluid is stored in a brake fluid reservoir normally located in the engine compartment.

There are two types of brakes:

Drum brakes slow your vehicle by the friction of a brake shoe pushing outward against the drum which is rotating with the wheel.

Disc brakes slow your car by the friction of a caliper pressing inward against a disc which is rotating with the wheel.

Both drum and disk brakes convert friction force to heat and if the brakes get too hot, they cease to work because they cannot dissipate enough heat. For both types of brakes, your stopping distance time is roughly proportional to the square of your speed, so if you double your speed you quadruple the distance to stop your car.

When you are stopped and apply your brakes, they lock. It is the friction force between the tires and the road that keeps you from moving. Your parking brake uses a cable rather than a hydraulic system to engage your brakes or clamp down on your drive shaft and will therefore function even if your service brakes have failed.

Anti-lock Braking Systems (ABS) are increasing in popularity and safety. The ABS is a hydro-electric system that sits on top of your conventional braking system. If the ABS should fail, you still have a fully-operational brake system.

The core of the ABS is a computer, which reads individual wheel speed, from sensors at each wheel. If the computer sees a rapid decrease in wheel speed, it translates that to a braking action. If one, or more, wheels apppears to be approaching "zero speed" (lock-up), the computer sends a message to the master cylinder solenoids to rapidly decrease/increse pressure to the affected wheels; in effect, the computer is rapidly "pumping" the brakes for you, up to 20 times per second.

The reason this is necessary is that a tire MUST be moving (rolling) in order to have what is called "rolling friction", which is required for steering. You cannot steer a locked up tire. (This is why skid marks always travel in a straight line, usually towards an object like a tree, telephone pole, or sign...that is what the driver was steering towards when they locked up the brakes). By rapidly pumping the brakes, the tire is allowed to roll, minimally, but enough to permit steering control, thus allowing a driver to escape hitting an offending object.

ABS brakes only work when the brake pedal is depressed, so the guiding principle of ABS is "STOMP, STAY, STEER", meaning stomp down on the pedal, stay on the pedal, and steer while braking.

Tachometer

Speedometer

Lighting

The Vehicle Code specifies:

It is important that your tail, brake, head, and turn lights be in good working order.

Headlights

You should use your headlights:

You should use your high-beam headlights whenever you are having trouble seeing with your normal headlights, except:

You must:

Turn Signals

You must signal before turning, changing lanes, or otherwise entering traffic from a side road or driveway.

You should signal during the last 100 feet before turning unless traffic conditions indicate you should start signaling earlier, such as on a freeway where you should signal for at least 5 seconds before changing lanes.

In addition to signaling the intention to make a turn, you must check your mirrors and blind spots to make sure it is safe to complete the maneuver.

You should not assume that just because you have signaled a turn or lane change that others can or will leave you the space to complete it.

You must signal even when you don't see any cars around.

You should use both arm signals and signal lights if it is difficult for others to see your signal lights.

If you plan to turn as soon as you leave an intersection, do not start signaling while you are approaching or in the intersection. Wait until you have crossed the intersection so as not to confuse traffic.

Make sure that your signal is turned off after you have completed your turn or lane change.

Other Lighting

It is illegal to drive with only your parking lights turned on .

You can use your hazard warning light flashers:

If emergency flashers are not available, you can tap your brake pedal so as to flash your brake lights to warn drivers behind you of a hazard ahead.

The purpose of backup lights is to:

Visibility Requirements

You should never drive a vehicle loaded in such a manner that:

You may not carry objects on a passenger vehicle that:

If you are towing a trailer or another vehicle, it must also have its own tail, brake, and turn lights that function simultaneously with those of your vehicle.

Braking Requirements

The Vehicle Code specifies braking distances that are required for vehicles. These standards differ for different sizes and weights of vehicles, and these distances will be greater for larger, heavier vehicles.

You should apply your brakes smoothly to avoid a locked-wheel skid.

Anticipate when you will need to stop so you can do so gradually. Smooth, gradual braking will:

A panel indicator showing "ABS" means that a vehicle is equipped with an antilock braking system. If you have an antilock braking system, you should keep constant pressure on the brake pedal while making an emergency stop.

If you do not have an antilock braking system, you should use threshold braking. Threshold braking means that you apply and release pressure on your brake pedal in small increments at the skidding threshold.

Windows, Mirrors, Defroster

The Vehicle Code provides specifications for the safe use of sun screening devices and tinting of windows. When cars are manufactured, they are in conformance with these specifications.

Any change in tinting or the modification or installation of sun screening devices must be done in accordance with the California Vehicle Code.

You must have mirrors which provide a view for at least 200 feet to the rear of your vehicle. Two mirrors are required on all vehicles. A left side mirror is required and either a rear view or right side mirror.

You should properly adjust your mirrors before starting to drive, to avoid being distracted while attempting to adjust them during driving.

Maintaining good visibility requires that you keep windshields and mirrors clean and free from obstructions. If your windshield is cracked and obstructs your view or that of your passenger, you will not be allowed to take your driving test. You must not carry objects, inside or outside, which obscure your view.

Over time windshield wipers lose their ability to effectively clean your windshield by cracking, loosing their flexibility, becoming dirty, and getting out of adjustment. Therefore, it is a safe practice is to change them annually.

Temperature and humidity conditions may change rapidly causing frost and condensation to quickly form on the windshield. For this reason, it is important to keep the defroster in good operating condition.

Horn

Vehicles are required to have a functioning horn or similar audible warning device. While the noise level of your horn must not be excessive, it must be audible under normal driving conditions for at least 200 feet from your vehicle.

It is appropriate to sound your horn:

It is not appropriate to sound your horn:

Tires

The minimum legal tread depth for tires is:

To avoid skidding, blowouts, and unsafe handling, the manufacturer's recommendations for your vehicle should be followed in selecting tires.

The manufacturer's recommendations for tire pressure should also be followed. Either over- or under-inflating tires:

Failing to keep wheels balanced and the suspension system properly aligned can lead to extremely rapid tire wear and may result in a blow-out.

Worn components in the suspension and steering systems of your vehicle can cause you to lose control of your vehicle as well as cause rapid tire wear.

The purpose of rotating tires is to prolong the life of the tire. Rotation should be done according to the intervals and procedures recommended by the manufacturer of your vehicle.

Peeling out or spinning your tires on fast starts:

Air Bags

Air bags, combined with lap/shoulder safety belts, offer the most effective safety protection available today for passenger vehicles. Air bags are designed to provide protection over and above what the seat belt provides. Air bags work best and afford maximum protection in tandem with seat belt use. Seat belts protect you in all crash situations.

Air bags, on the other hand, are designed to provide extra protection only in frontal crash situations because people are far more likely to die in a frontal crash than in any other type of crash.

Crash sensors trigger air bag deployment when your vehicle experiences a significant frontal or near frontal impact. This causes the solid chemicals within the module to convert to harmless nitrogen gas in a chemical reaction. The expanding gas fills the bag, which opens the cover on the steering wheel hub or the dashboard. When fully expanded, the bag absorbs the forces that the body would normally absorb in the crash. The air bag protects the head and upper body from striking the steering wheel, dashboard or windshield.

Most air bag deaths have involved people who weren't using belts, were using them incorrectly, or were positioned improperly.

For the maximum air bag protection:

Always seat children in the back seat when possible, even if there is no airbag in front of them. Avoid putting children in the front seat of a car equipped with airbags. Children sitting in the front seat with an air bag could be severely injured by the airbag.

Even when kids get older, riding in the back seat is safer. Never install a rear-facing infant safety seat in the front seat of a car equipped with passenger-side air bags, unless the vehicle is equipped with a disabling switch and the switch is in the "off" position.

If you must put a child in the front seat, then an airbag on/off switch is essential. If there are too many children to all sit in back, make sure the seat is all the way back and the child is securely buckled and sitting back in the seat.

Tire Maintenance

Tires should be frequently inspected for proper inflation pressure, tread depth, uneven wear, and cracks. They should be replaced when tread depth is low or they are cracked.

If uneven wear is present you should check inflation pressure and/or wheel balance and alignment of your vehicle . Have any problems corrected immediately or you may be forced to purchase new tires.

Electrical Maintenance

If the electrolyte in your battery can be refilled, it should be checked and refilled with distilled water as part of regular maintenance on your vehicle in order to keep the battery functioning. Electrolyte fluid is corrosive and can severely injure your eyes. Batteries generate hydrogen gas which can explode when the battery caps are removed.

If your alternator belt is slipping or breaks, your battery will discharge, lights and other accessories may not work, and the vehicle will eventually stall. The belt tension should be maintained according to manufacturer specifications for the alternator to perform correctly and to prolong the life of the belt. Cracked belts should be replaced.

Exterior lights should be regularly checked for burned out bulbs that you may not be aware of from inside the vehicle. Interior lights are necessary to see displays both at night and during the day, are essential in case of an emergency at night, and must be maintained in proper working order. It is illegal to drive with headlights that are not properly adjusted.

It is important to be sure your windshield wiper motor is working and that the linkages to the wipers are functioning. The time to discover there is a problem is not when you need them.

Leaks in your fuel system can cause fires and expose you to toxic gases. The leaks can occur in the fuel tank, fuel lines, fuel pump, carburetor, fuel injector lines and by not having your gas cap securely attached.

Dashboard & Controls Symbols

On September 23, 2003, the National Highway traffic Safety Administration issued a proposal, included into the Federal Register, that sets standards for icons and symbols used to transmit information to the driver and occupants of a vehicle. These symbols are more readily understood by all drivers, irrespective of native language. These are based on ISO Standards 2575.

Because the proposal covers cars, buses, and trucks, we have not included all possible icons, but have tried to include the most commonly seen on today's vehicles, in alphabetical order.

Starting with this page and continue with the next few pages, review the Symbols in alphabetical order.

Dashboard & Controls Symbols

Dashboard & Controls Symbols

Dashboard & Controls Symbols

Dashboard & Controls Symbols

Dashboard & Controls Symbols

Safety AidsToday's society is on the move, and the automobile allows us to go farther from home. As a result, we often find ourselves in unforeseen predicaments. Preparing for them is the best way to survive them.

Your car should always have, handy in the trunk, the following minimal items:

Basic Auto MaintenancePeriodic lubrication and oil changes according to manufacturer's recommendations extend the life of your vehicle, allow you to avoid costly repairs, and prevent dangerous break-downs.

The weight of oil that you choose for your engine (e.g., 10w-30 or 20w-50) depends on the manufacturer's recommendations, the outside temperature, and the age of your vehicle. Make sure to choose the right weight of oil for your vehicle.

Your vehicle uses oil in more than just the engine. Your transmission, differential, and power steering (of equipped) also use fluid that must be periodically checked and changed. Make sure to use the right type of fluid for each.

Failure or degraded performance of your brakes can lead to accidents. Your brakes should be inspected and maintained according to manufacturer's specifications.

You should periodically check the level of your brake fluid and maintain a full level. Periodically change your brake fluid according to the recommendations of your vehicle's manufacturer. Only use the weight of brake fluid they recommend.

Periodic tune-ups and transmission service according to manufacturer's specifications extends the life of your vehicle, allows you to avoid costly repairs, and prevents dangerous breakdowns.

During a tune up you should have your spark plugs, spark distributor, distributor cap, and air filter changed. The timing of your vehicle should be check and adjusted, and your points should be changed (if your vehicle has them).

To avoid breakdowns, accidents, and costly repairs, you should be aware of the condition of your steering system. There should be no play in your steering wheel if you have power steering, and no more than 2 inches of play in your steering wheel if you do not have power steering. If this is not the case, you should have your vehicle checked-out by a qualified technician.

Vibrations, unusual noises from your wheels, and your vehicle pulling or swerving when you stop or turn all indicate possible problems in your suspension system, steering system, brake system, and/or wheels and tires. These problems are largely avoided by inspection and repair at regular intervals.

You should also check for fluid leaks from your shocks and/or struts. If fluid is leaking, you should have them replaced.

Breakdowns, accidents and costly repairs are avoided by keeping your cooling system in good working order. This involves maintaining the level of the coolant and changing it according to manufacturer's recommendations.

You should also check for coolant leaks, cracks and deterioration in hoses and belts, and noises and leaks from your water pump.

You should replace hoses and belts periodically (say, once every three years). Be aware of abrupt changes or trends in your engine temperature as indicated by the temperature gauge. These signal developing problems.

Breakdowns and costly repairs can be avoided by keeping your exhaust system in good working order. This includes realizing that changes in noise level, smelling an abnormal amount of fumes, and rattling underneath your vehicle signal problems with your exhaust system. The exhaust system should be inspected for leaks and secure attachment along with other regular maintenance.

It is illegal to modify your exhaust system so as to increase the noise level of your vehicle or install a by-pass devise that allows it to increase. Your exhaust system should not have leaks that increase the noise level. Leaks in your exhaust system are dangerous because they expose you to carbon monoxide and other toxic gases.

The law requires (in most cases) that you have an emission test every two years at the time of registration or at time of sale. It is a good idea to have your smog control components checked at the time of a tune-up.

The California Vehicle Code provides specifications for fenders and mudguards on your vehicle. Before modifying these features of your vehicle, you must check the requirements in the California Vehicle Code . Modifying these components could result in throwing rocks or debris at the car behind you.

The notion of preventative maintenance is that money is saved and breakdowns are avoided by having comprehensive inspections done regularly (say, twice a year). Have parts with high failure rates replaced even though they are still functioning is also a good idea.

Examples of preventative maintenance include:

Economical & Safe Use of the Automobile

There are several things you can do to maximize the economic operation of your motor vehicle.

First, you should avoid making fast starts and stops, and cornering too fast. They are not only unsafe, but increase the cost of operating and maintaining your vehicle by wasting fuel and wearing out tires and brakes.

The second thing you can do to save money is to drive slower. Faster driving requires more fuel to get you the same distance. Obey speed limits and you will save fuel and reduce the risk to others.

Another thing you can do is anticipate when you will need to stop. Quick braking excessively wears your brakes and tires. Look ahead while you are driving so you can anticipate when you will need to stop and do so smoothly and gently.

Periodic or preventative maintenance of your vehicle will also lower your long-term operation costs. Periodic tune ups reduce fuel consumption by making your vehicle run more efficiently. The money you spend on periodic maintenance can also save you large expenses due to major engine failure and breakdown.

The cost of owning and operating a vehicle is the sum of those costs directly related to the number of miles driven (gasoline, replacing tires and other components that wear out with use, and oil changes), and costs that are largely the same regardless of how little you actually drive your car (insurance, registration, depreciation, and maintenance that must be performed regardless of miles driven).

Depreciation is a significant cost in owning a vehicle. Depreciation is the amount you have paid for the privilege of owning and driving the vehicle in addition to what you have paid for gas, maintenance, insurance, and so on. As your car accumulates more miles or gets older (regardless of how many miles it has been driven), it is worth less when you sell it.

Depreciation is particularly high during the period immediately after buying a new car, and the yearly depreciation cost decreases as the car gets older. If you drive your car very little, gas mileage, and maintenance may not be a significant consideration, but depreciation, insurance, and registration will be. If you drive your car a lot, gas mileage and day-to-day repairs will be significant cost considerations. While it is difficult to estimate the costs of owning and operating a vehicle precisely, you should consider all of these types of costs when making a decision about what type of vehicle to purchase.

In selecting a vehicle you must consider how you will use it in your work, recreation, the number and age of passengers to be transported, and the need for dependability. It is important to consider all the costs of owning and operating a vehicle, not just the price you are paying, when determining whether you can afford the car.

If you buy a new rather than used car, your costs for financing, depreciation, registration, and insurance will be higher, but your maintenance costs will probably be lower, the dependability of the vehicle will probably be better, and the crash worthiness and fuel efficiency may be better.

It is wise to have a used vehicle inspected for mechanical condition prior to purchase.

When purchasing a vehicle from a dealer, the dealer submits fees, use tax, and other documents to register the vehicle with the DMV. When purchasing from a private party, the seller provides a bill of sale, smog certification, and an endorsed Certificate of Title, and submits a Notice of Release of Liability to the DMV within 5 days. The buyer pays the use tax and is responsible for registering vehicle with the DMV within 10 days.

If you finance a car, the interest you pay on the money you have borrowed may be significant. You may be required to pay for insurance that you would not have otherwise chosen, and if you fail to make payments, the car can be repossessed and your credit history damaged.

If a minor is allowed to drive your vehicle, it may significantly increase the insurance premiums. Your insurance may not be sufficient to pay for the damages for which you are liable if the minor causes an accident.

There are some common sense rules you can follow which will generally steer you clear of dangerous situations when operating a motor vehicle. The following tips are presented to help insure your personal safety while driving.

Always lock your car doors while driving, and roll windows up far enough to keep anyone from reaching inside.

At stop signs and lights keep the car in gear and stay alert.

Travel well-lighted, busy streets. You can spare those extra minutes it may take to avoid an unsafe area.

Keep your purse and other valuables out of sight, even when you are driving in your locked car.

Park in safe, well-lighted areas near your destination. Always lock your car, even for a short absence. And before unlocking your car, quickly check to make sure no one is hiding on your seats or floors, front and back.

Never pick up a hitchhiker. Even the most harmless-looking stranger can be dangerous. Don't find out.

When you arrive home, leave your headlights on until you have the car in the garage and the house door unlocked. If you can, have a remote control garage door opener installed; it will allow you to remain in your locked car until you're inside your locked garage.

Check the daily routes you travel and pick out safe spots-24 hour gas stations, convenience stores, and police and fire stations. If trouble should arise, drive straight to one of these locations.

Here are some facts about vehicle theft:

If you take the following protective measures, you may deter the theft of your vehicle. Generally, thieves will have to look far for an easier target.

To help avoid having your vehicle stolen:

Engrave an identifying number on a hidden place on the car and on any valuable components to help the police identify recovered property.