Deck 5: Computers and Input Sensors

Question 1

The major difference in the air/fuel sensor operation compared to the conventional oxygen sensor is in the signal generated to the PCM.

Answer 1

True

Question 2

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

Answer 2

C

Question 3

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

Answer 3

True

Question 4

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 5

Technician A says that low compression on an engine cylinder can be successfully compensated for by the PCM with no adverse effect on performance or emissions. Technician B says that the PCM and catalytic converter can mask or hide some basic engine defects. Who is correct?

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

Question 6

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 7

The OBD II test strategies compare sensor inputs to one another during a rationality test.

Question 8

The air/fuel ratio sensor produces what type of output signal?

A) a square wave signal.
B) a fluctuating high/low voltage signal.
C) both A and B
D) a continuous signal that varies with the oxygen content of the exhaust stream

Question 9

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

Question 10

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 11

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

Question 12

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 13

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

Question 14

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

Question 15

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 16

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

Question 17

The power train control module may be found everywhere on the vehicle, EXCEPT:

A) the passenger compartment
B) the inner fender
C) the driver's door
D) the firewall

Question 18

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

Question 19

Technician A says that a MAF may contain either an electrically heated hot wire or film. Technician B says that the PCM changes the current supplied to the MAF sensor in order to maintain the hot wire or hot film temperature. Who is correct?

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

Question 20

The wide range air/fuel ratio sensor (AFS) heater element circuit operates very similarly to that of an oxygen sensor's heater element circuit.

Question 21

How is network data transmission speed expressed?

Question 22

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

Question 23

What is an EEPROM, and how does it differ from older versions?

Question 24

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

Question 25

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

Question 26

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

Question 27

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 28

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

Question 29

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

Question 30

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

Question 31

What is the major difference in the air/fuel sensor operation over the conventional oxygen sensor?

Question 32

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

Question 33

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

Question 34

What is a controller area network (CAN)?

Question 35

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

Question 36

If the malfunction indicator light is on and a DTC P0131 is stored for O2 Sensor Circuit Low Voltage (Bank 1 Sensor 1), what is the most likely cause for this code to be set?

A) EGR valve stuck open
B) EVAP purge solenoid stuck open
C) vacuum leak
D) high fuel pressure