Question 1

Technician A says that before performing proprietary reprogramming of an engine ECM, any fault codes should be cleared. Technician B says that in some cases following a proprietary data reprogramming procedure, a verification file has to be uploaded to the OEM data huB. ho is right?

Accepted Answer

A)  Technician A only 
B)  Technician B only 
C)  Both A and B. 
D)  Neither A nor B

Question 2

When an engine turns at 2000 rpm, how long does it take to complete one full revolution?

Accepted Answer

A)  0.003 seconds 
B)  0.030 seconds 
C)  0.300 seconds 
D)  30 nano seconds

Question 3

What type of mass airflow (MAF) sensor measures pressure differential at two points either side of a venturi?

Accepted Answer

A)  hot wire 
B)  critical flow venturi 
C)  vortex airflow 
D)  eddy current

Question 4

Technician A says that Hall-effect throttle position sensors (TPS) are configurable to either digital or analog input circuits as required by the application. Technician B says that a disadvantage of Hall-effect TPS is that the contact wiper wears at an accelerated rate. Who is correct?

Accepted Answer

A)  Technician A only 
B)  Technician B only 
C)  Both A and B 
D)  Neither A nor B

Question 5

Technician A says that some OEMs used the term flash memory to describe any type of programmable onboard memory. Technician B says that true flash memory transfers more quickly than EEPROM because it batched in blocks of bytes. Who is correct?

Accepted Answer

A)  Technician A only 
B)  Technician B only 
C)  Both A and B 
D)  Neither A nor B

Question 6

What is a stepper motor used for?

Accepted Answer

A)  precision positioning of a shaft 
B)  precisely controlling rpm 
C)  linear proportioning of an actuator 
D)  climate control fan speed

Question 7

What type of output does an induction pulse generator (used to read shaft or rotor speed) produce?

Accepted Answer

A)  AC 
B)  DC 
C)  PWM 
D)  constant frequency

Question 8

Which of the following best describes the function of a Freightliner central gateway??

Accepted Answer

A)  ?Enables communications between J1939 and other chassis data buses 
B)  ?Required to permit geofence V2V communications 
C)  ?Termination block to damp electronic noise 
D)  ?Any DDL access socket

Question 9

Which of the following is commonly used to convert the results of ECM processing into action?

Accepted Answer

A)  sensors 
B)  actuators 
C)  potentiometers 
D)  thermistors

Question 10

Which of the following memory categories is designed to be the most permanent?

Accepted Answer

A)  RAM 
B)  ROM 
C)  PROM 
D)  EEPROM

Question 11

An engine management system that has adapted existing hydromechanical fueling devices for control by computer is known as:

Accepted Answer

A)  hybrid 
B)  semi-cybernetic 
C)  partial authority 
D)  retrofitted

Question 12

When a stepper motor is driven by an 8 bit controller, how many 'steps' in the rotation can its rotor be positioned in?

Accepted Answer

A)  8 
B)  64 
C)  128 
D)  256

Question 13

The non-volatile, read/write/erase memory component in a truck ECM is known as:

Accepted Answer

A)  ROM 
B)  PROM 
C)  EEPROM 
D)  DVD

Question 14

Technician A says that some types of NOx sensor use a galvanic operating principle. Technician B says that galvanic type NOx sensors must be powered up using V-Ref. Who is correct?

Accepted Answer

A)  Technician A only 
B)  Technician B only 
C)  Both A and B 
D)  Neither A nor B

Question 15

Which of the following inputs to an engine management ECM would be most likely categorized as foreground processing?

Accepted Answer

A)  coolant temperature 
B)  oil temperature 
C)  rail fuel pressure 
D)  throttle position sensor

Question 16

Technician A says that a WIF sensor uses a couple of probes that measure the dielectric properties of water versus that of fuel. Technician B says that dielectric properties refers to electrical resistivity. Who is correct?

Accepted Answer

A)  Technician A only 
B)  Technician B only 
C)  Both A and B 
D)  Neither A nor B

Question 17

?Which of the following best describes the function of a Freightliner central gateway?

Accepted Answer

A)  ?Enables communications between J1939 and other chassis data buses 
B)  ?Required to permit geofence V2V communications 
C)  ?Termination block to damp electronic noise 
D)  ?Any DDL access socket

Question 18

Which of the following categories of devices is used to signal input data to an ECM during engine operation?

Accepted Answer

A)  sensors 
B)  actuators 
C)  drivers 
D)  scan tools

Question 19

When the piezo stack in a piezo-actuator is hit with an electrical trigger, which of the following best describes the time required for a mechanical response?

Accepted Answer

A)  almost instantly 
B)  lagged by time required to build field 
C)  lagged by time required to overcome counter electro-motive force (CEMF) 
D)  slower than an equivalent solenoid actuator

Question 20

In which of the following output devices would you be more likely to find a piezo actuator?

Accepted Answer

A)  linear proportioning solenoid 
B)  electrohydraulic injector (EHI) 
C)  non-contact TPS 
D)  stepper motor

Exam 33: Vehicle Computer Systems

Technician A says that before performing proprietary reprogramming of an engine ECM, any fault codes should be cleared. Technician B says that in some cases following a proprietary data reprogramming procedure, a verification file has to be uploaded to the OEM data huB. ho is right?

When an engine turns at 2000 rpm, how long does it take to complete one full revolution?

What type of mass airflow (MAF) sensor measures pressure differential at two points either side of a venturi?

Technician A says that Hall-effect throttle position sensors (TPS) are configurable to either digital or analog input circuits as required by the application. Technician B says that a disadvantage of Hall-effect TPS is that the contact wiper wears at an accelerated rate. Who is correct?

Technician A says that some OEMs used the term flash memory to describe any type of programmable onboard memory. Technician B says that true flash memory transfers more quickly than EEPROM because it batched in blocks of bytes. Who is correct?

What is a stepper motor used for?

What type of output does an induction pulse generator (used to read shaft or rotor speed) produce?

Which of the following best describes the function of a Freightliner central gateway??

Which of the following is commonly used to convert the results of ECM processing into action?

Which of the following memory categories is designed to be the most permanent?

An engine management system that has adapted existing hydromechanical fueling devices for control by computer is known as:

When a stepper motor is driven by an 8 bit controller, how many 'steps' in the rotation can its rotor be positioned in?

The non-volatile, read/write/erase memory component in a truck ECM is known as:

Technician A says that some types of NOx sensor use a galvanic operating principle. Technician B says that galvanic type NOx sensors must be powered up using V-Ref. Who is correct?

Which of the following inputs to an engine management ECM would be most likely categorized as foreground processing?

Technician A says that a WIF sensor uses a couple of probes that measure the dielectric properties of water versus that of fuel. Technician B says that dielectric properties refers to electrical resistivity. Who is correct?

?Which of the following best describes the function of a Freightliner central gateway?

Which of the following categories of devices is used to signal input data to an ECM during engine operation?

When the piezo stack in a piezo-actuator is hit with an electrical trigger, which of the following best describes the time required for a mechanical response?

In which of the following output devices would you be more likely to find a piezo actuator?