Ignition system

The air fuel mixture by weight is about _____________ parts to 1.

15

The potentiometer can be linear or circular in construction and has ________electrical connecting points.

3

High-voltage systems have a number of advantages over low-voltage systems, including:

All of the above

In a good circuit, the resistance of the _____ is very low, causing small and insignificant amounts of voltage drop.

All of the above

Inputs to the PCM include ______________ and the air-conditioning switch.

All of the above

Jumper leads are used to extend connections

Any of the above

Tech A says a resistor is a component designed to extract energy from the current flow. Tech B says he uses a voltmeter to check for a voltage drop. Who is correct?

Both

Tech A states that engine management systems were born out of a need for greater efficiency and emission control. Tech B states that the engine management system controls the operation of the engine and all of its related system. Who is correct?

Both

Tech A states that the PCM has the ability to learn from its actions and to use that information to make better decisions in the future. Tech B states that it can also perform basic self-diagnostics on virtually all of the components in the system. Who is correct?

Both

Tech A states that the PCM of an engine gathers information from various sensors and components. Tech B states that the PCM can also processes that information based on stored data and command components to operate in specified ways. Who is correct?

Both

Two technicians are discussing scope testing. Tech A says that the vertical axis of the screen shows voltage. Tech B says that the horizontal axis shows time. Who is correct?

Both

A(n) ________ system was a mechanical ignition system with a switch, called contact breaker points.

Contact breaker point ignition

The data processor function of a PCM receives the data from the input signal processing section and compares it to ________ in the memory.

Data maps

In contact breaker point ignition systems, the ________ rotates at half the speed of the crankshaft and distributes the high voltage from the ignition coil and spark plugs. Select one:

Distributer

A(n) ________ may be used to check signal voltages from sensors used on the vehicle warning devices.

Either A or B

A lean air fuel mixture has less air in proportion to the amount of fuel.

False

Digital storage oscilloscopes (DSOs) cannot display waveforms as they occur; they store the waveform for later analysis.

False

If an engine cranks but will not start, the crankshaft and camshaft positions should be tested before performing a spark test.

False

Ignition systems operate according to the laws of induction observed by:

Faraday

The PCM of an engine is comprised of all of the following parts EXCEPT:

Feedback control section

Which node of the PCM translates information from, or to, the other networks so that it can be shared between networks?

Gateway node

The mass air-flow sensor can measure the air entering the engine down to a(n) _____________ per second.

Gram

During combustion, as the piston finishes compressing the air fuel mixture and ignition occurs, the flame spreads faster and moves evenly to _________ the mixture, and the piston reaches top dead center.

Halfway through

The ________ connect the coil to the distributor cap center terminal and the distributor cap side terminals to the terminals on the top of the spark plugs.

High tension leads

In electronic ignition systems, a(n) __________ uses a power transistor to turn the primary circuit on and off.

Ignition module

The ________ steps up the low voltage in the primary circuit to the high voltage in the secondary circuit.

Induction coil

A 20:1 attenuator divides the amount of voltage passing through it by a factor of 20. Thus, 20 volts _____ will appear as an _____ of 1 volt.

Input and output

If the reach is too ________, the piston may strike the spark plug while moving up.

Long

The barometric pressure (BARO) sensor works in conjunction with the:

MAP

The ________ section of a PCM contains the software for the computer, as well as a place to retain diagnostic trouble codes (DTCs), freeze-frame data, and learned data.

Memory and storage

Some modules are grounded through their ________, so it is important that the module is clean and fastened securely.

Mounting hardware

Tech A says that engine misfiring will cause a lean exhaust condition. Tech B says that engine misfiring can cause overheating of the catalytic converter. Who is correct?

NOT both

Tech A says that spark plug heat range is how much heat spark plugs can physically handle. Tech B says using the wrong heat range plug can result in spark plug damage. Who is correct?

NOT both

Older ignition systems used a mechanical advance that was typically controlled by:

NOT breaker plates

Tech A says that in modern vehicles, an oxygen sensor is only positioned in the exhaust pipe after the catalytic converter. Tech B says that the oxygen sensor provides the electronic body control module (EBCM) with an electrical signal that relates to the amount of oxygen in the exhaust gas. Who is correct?

Neither

Tech A states that digital signals are continuously variable, typically changing in strength and time. Tech B states that an analog signal is a direct on/off with no in-between transition. Who is correct?

Neither

Tech A says that any vehicle made after 1976 will use two oxygen sensors. Tech B says that oxygen sensors are located in the intake manifold. Who is correct?

Niether

Finding breakdowns in coil insulation requires the coil to be activated and the available voltage to be measured on a(n) ________ and compared to specifications.

O-scope

A ________ shows all the cylinders firing in sequence.

Parade pattern

The on and off time of a stepper motor relates to its duty cycle, which is generally expressed as a:

Percentage

If there is no power to the ________ side and/or no switching at the ________ side, the ignition coil or primary wiring may be defective.

Positive:negative

Because the value of the self-induced voltage in the ________ is also influenced by the rate of collapse of the magnetic field, which is determined by the rate of change of the current flow through the coil, it is essential that the ______ be switched off as quickly as possible.

Primary winding;primary current

The reduction in voltage and current to the load ____________ the amount of electrical power to the load, affecting its performance.

Reduces

In many cases, the software in the PCM's memory can be updated by uploading software updates, called a ________ process.

Reflash

The power train control module (PCM) must control a high-current fuel pump. The best actuator to use would be a:

Relay

Manufacturers design their ignition systems to have an amount of ________ above the ________ so that misfire is prevented. Select one:

Reserve voltage; required voltage

If it is an inductive-type sensor, use an ohmmeter to read ________.

Resistance

Protection devices like fuses and fusible links are _____, meaning that if excessive current flows, they __________.

Sacrificial; will blow or trip and have to be replaced

The condition in which the magnetic field is completely built is called coil ________. Select one:

Saturation

When taking DC current measurements, always remember that an ammeter must be connected in ______________ within the circuit.

Series

The ____ of all the voltage drops in a _____ equals the supply voltage.

Sum; series circuit

Spark plugs either use a ________ design or a washer type of gasket to form a seal between the spark plug and the cylinder head.

Taper

Tech A says an example of a series-parallel circuit is the brake light circuit. Tech B says when testing, you only need to consider the voltage drop across the parallel branch. Who is correct?

Tech A

Tech A says in a parallel circuit, the more branches that are added, the more current flow increases. Tech B says a series-parallel circuit is made of parallel circuits only. Who is correct?

Tech A

Tech A says that spark ignition typically occurs before TDC. Tech B says that spark ignition typically occurs after TDC. Who is correct?

Tech A

Technician A says an oscilloscope is commonly referred to as a lab scope or just scope. Technician B says lab scopes are not very important test instruments in a modern automobile. Who is correct?

Tech A

Two technicians are discussing a series light circuit. Technician A states that if the fuse blows, available voltage after the fuse will be 0 volts. Technician B states that the voltage drop over the fuse will be 0 volts. Which technician is correct?

Tech A

Two technicians are testing a series capacitor circuit. Their measurements are as follows: V1=12V; V2=0; A1=0. Technician A states that this could indicate that the second capacitor is fully charged. Technician B states that this could indicate that the lamp is burned out. Which technician is correct?

Tech A

Tech A says that a lambda greater than 1 means the engine is running rich. Tech B says that the amount of oxygen in the exhaust indicates how rich or lean the mixture is. Who is correct?

Tech B

Tech A says that a relay is a one-way electrical check valve used in alternators to change AC into DC. Tech B says that a relay uses electromagnetism to open or close a switch. Who is correct?

Tech B

Tech A says that coil-on-plug ignition systems use one coil to fire two cylinders. Tech B says that you should twist spark plug boots before removing them. Who is correct?

Tech B

Tech A says that the positive side of the coil primary circuit is switched. Tech B says that the negative side of the coil primary circuit is switched. Who is correct?

Tech B

Tech A says that total resistance goes up as more parallel paths are added. Tech B says that total amperage goes up as more parallel paths are added. Who is correct?

Tech B

Tech A states that CAT ratings were designed initially for automotive meters. Tech B states that hybrid vehicles typically require meters and test leads rated as CAT III or CAT IV. Who is correct?

Tech B

Tech A states that modern vehicles make use of a distributor to create the spark. Tech B states that modern vehicles no longer use a distributor. Who is correct?

Tech B

_______ circuits are found in vehicles, such as in dash light dimmer circuits, although they are not as common as _______ circuits.

The correct answer is: Series-parallel; parallel

Which component of the contact breaker point ignition system provides the driver control over system operation?

The ignition switch

A low firing line indicates low resistance, a short in the circuit, or low compression.

True

Adding extra paths reduces the circuit's total resistance to current flow.

True

If the wire is wound into a coil, the magnetic fields combine to create a stronger and denser magnetic field, with a north and a south pole, just like a permanent magnet.

True

In automotive applications, the circular form is commonly used as a throttle position sensor, with the center contact attached to the throttle plate.

True

Induction-type systems are electronic systems that use a magnetic pulse generator to generate an AC signal. Select one:

True

Most modern vehicles use a 12-volt lead acid rechargeable battery located in the engine compartment, in the trunk, or under the rear seats.

True

The DVOM can be connected in various parts of a series circuit to measure the current flow.

True

The advent of digital technology has given rise to higher powered processors that allow better control and monitoring of the systems on the vehicle, including the fuel injection system.

True

Usually, a fuse contains a metal strip that is designed to overheat and melt when subjected to a specified excessive level of current flow, breaking the circuit and stopping the excessive current flow from potentially damaging the wiring harness and more valuable components. Select one:

True

When cycled very quickly, digital signals can be used to create a(n) ________, similar to the variable control provided by an analog signal.

Varying output control signal

A drive cycle includes all of these EXCEPT:

Vehicle cold soak

As the stationary winding of induction-type systems is influenced by the magnetic field, a ________ is induced in the winding each time the ________ changes.

Voltage, magnetic field

Continuity is:

a continuous circuit.

Electronic fuel injection and engine management systems can adjust the ________mixture within certain limits as parts wear and thereby maintain proper control of the air fuel ratio over a broad range of conditions.

air fuel

DSO stands for:

digital storage oscilloscopes

The ________ of a PCM typically sends either simple on/off signals or pulse width-modulated signals to the actuators, depending on the actuator being controlled.

output drivers section

What do some sensors use to create a variable voltage signal that corresponds to a specific condition?

potenieometer

variation in pulse width at a fixed frequency is called:

pulse width modulation

When doing a voltage drop test, you should do all these EXCEPT:

remove the positive battery cable.

Ideally, combustion would completely burn all of the fuel that entered the cylinder, extracting the maximum thermal energy from the gasoline.

true

Non-powered test lamps are useful in determining whether electrical power is present in a part of a circuit.

true

All these statements are true about protection devices EXCEPT:

you should always replace blown fuses with a fuse of a higher amp rating