Deck 5: Computers and Input Sensors

Question 1

The air/fuel ratio sensor produces a voltage output relative to:

A) the air-fuel mixture in the cylinders
B) the intake air temperature
C) both A and B
D) the oxygen content of the exhaust stream

Answer 1

D

Question 2

Mass air flow sensor voltage corresponds to:

A) engine load and crankshaft speed
B) throttle opening and engine load
C) engine and vehicle speed
D) engine load and camshaft speed

Answer 2

B

Question 3

Since the early 2000s, the wide-range air-fuel ratio sensor (AFS) has replaced the conventional zirconia oxygen sensor.

Answer 3

True

Question 4

Technician A says that in a fuel injection system, the MAF sensors may be vane-type, heated grid-type, or hot wire-type. Technician B says that the PCM supplies a richer air-fuel ratio when it gets a signal that current flow is increasing to maintain temperature in the MAF module. Who is correct?

A) A only
B) B only
C) both A and B
D) neither A nor B

Question 5

The OBD II test strategies compare sensor inputs to one another during a rationality test to see if the inputs make sense with the expected outcome .

Question 6

The coolant temperature sensor is a negative temperature coefficient sensor; therefore:

A) as temperature increases, resistance increases
B) as temperature increases, the amplitude of the sine wave increases
C) as temperature increases, resistance decreases
D) as temperature decreases, the amplitude of the sine wave increases

Question 7

A twisted pair of wires helps to eliminate the induction of electro-magnetic-interference (EMF).

Question 8

Technician A says that when the voltage output of an air/fuel ratio sensor shifts below 3.3 V, it indicates a rich air/fuel mixture ratio. Technician B says that when the voltage output of an air/fuel ratio sensor shifts below 3.3 V, it indicates a lean air/fuel mixture ratio. Who is correct?

A) A only
B) B only
C) both A and B
D) neither A nor B

Question 9

Prior to OBD II, many automotive PCMs used an unalterable programmable read-only memory (PROM).

Question 10

OBD II can store information about adjustments the PCM has made for component wear and varied operating conditions. The ability of OBD II to adjust calibrations to compensate for these defects and less-than-ideal conditions is known as:

A) compensatory regulation
B) modification component
C) adaptive strategy
D) adjustment capacity

Question 11

The air-fuel ratio sensor (AFS) has the ability to measure air-fuel ratios from as lean as 35:1 to as rich as 11:1.

Question 12

Physically, the air/fuel ratio sensor looks very similar to a conventional oxygen sensor from the outside.

Question 13

The air/fuel ratio sensor (AFS) circuit can be measured directly with a digital multimeter with accuracy.

Question 14

Technician A says that when a DTC is cleared from the PCM memory, the system readiness monitors are also cleared. Technician B says that after an emissions repair is completed, the DTCs stored should be cleared from the PCM. Who is correct?

A) A only
B) B only
C) both A and B
D) neither A nor B

Question 15

Technician A says that a digital voltage signal is continuously variable within a certain voltage range. Technician B says an amplification circuit in the input conditioning chip will amplify a low voltage signal. Who is correct?

A) A only
B) B only
C) both A and B
D) neither A nor B

Question 16

Most of today's computers utilize a technology that allows for electronically erasable programmable read-only memory (EEPROM).

Question 17

A serial data stream is an analog code that is known as a binary code.

Question 18

An air/fuel ratio sensor is used instead of a conventional oxygen sensor because:

A) the air/fuel ratio sensor does not require a heater element
B) an air/fuel ratio sensor allows for more accurate fuel control
C) an air/fuel ratio sensor is less expensive than a conventional oxygen sensor
D) none of the above

Question 19

The AFS operating temperature is 750°F (400°C), which is substantially colder than the conventional oxygen sensor operational temperature of 1200°F (650°C).

Question 20

Technician A says that the conventional oxygen sensor produces a fluctuating high/low voltage signal. Technician B says an air/fuel ratio sensor produces a more constant output signal voltage. Who is correct?

A) A only
B) B only
C) both A and B
D) neither A nor B

Question 21

What is the circuit over which serial data is transmitted called?

Question 22

What is EEPROM memory, and how does it differ from older PROM memory?

Question 23

Why would an air/fuel ratio sensor be used instead of a conventional oxygen sensor?

Question 24

What is the special software program called that is designed to manage the operation of all system monitors?

Question 25

What is each one (1) or zero (0) in a data stream is referred to as?

Question 26

What type of tools may be used to monitor the operation of a conventional oxygen sensor?

Question 27

How does the air/fuel sensor generate a signal to the PCM and how does the PCM respond?

Question 28

What is a controller area network (CAN)?

Question 29

A baseline is performed by driving a vehicle or placing it on a dynamometer and driving a repeatable drive cycle that includes all of the following except:

A) idling
B) 2500 rpm no load
C) steady cruise heavy load
D) acceleration

Question 30

What sensor has the wide range air/fuel ratio sensor (AFS) taken the place of?

Question 31

What is a speed density program and how does it work?

Question 32

What is the process called that changes an analog signal, such as a variable voltage signal, into a digital binary code signal?

Question 33

What is the PCM test called that compares sensor inputs to one another to see if the information makes sense when analyzed as a group?

Question 34

How is network data transmission speed expressed?

Question 35

What are the three speed categories of serial data transfer specified for CAN systems?

Question 36

What is the CAN protocol, and how is it standardized?