Deck 9: Diagnosing 4wd and Awd Control Systems Advanced Four-Wheel-Drive Systems

Question 1

Technician A says viscous clutch biasing sends torque to the wheel with the least traction. Technician B says it will send torque to the wheel with the greatest traction. Who is correct?

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

Answer 1

B

Question 2

When shifting from 4WD Auto to 4WD Low, most vehicles must be brought to a stop.

Answer 2

True

Question 3

A device which allows the front and rear axles to rotate at different speeds in full-time 4WD and AWD systems works to eliminate driveline windup.

Answer 3

True

Question 4

Viscous coupling differentials send power to the axle or wheel that has the least traction.

Question 5

Technician A says operating a vehicle in 4WD-Low on dry pavement increases tire wear. Technician B says driveline components may be damaged by operating in 4WD-High on drive pavement. Who is correct?

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

Question 6

A viscous coupling must be used with a center differential.

Question 7

Which statement concerning turning a corner with a 4WD system is correct?

A) The rear wheels move through a wider arc than the front wheels.
B) The front wheels travel a greater distance than the rear wheels.
C) The right rear wheel travels the greatest distance.
D) The left rear wheel travels the greatest distance.

Question 8

During turns, the front wheels travel a shorter distance than the rear wheels.

Question 9

Technician A says all-wheel drive vehicles spread the tractive effort to all four driving wheels. Technician B says all-wheel drive vehicles operating under normal conditions are driving in 2WD. Who is correct?

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

Question 10

AWD constantly provides power to front- and rear-drive axles.

Question 11

Many AWD vehicles are based on _____ vehicles.

A) FWD
B) RWD
C) 4WD
D) hybrid

Question 12

Technician A says the interaxle differential solves the problem of driveline windup during turns. Technician B says the interaxle differential increases performance in poor traction conditions. Who is correct?

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

Question 13

Technician A says part-time four-wheel drive systems are manually operated. Technician B says all four-wheel drive systems are automatically controlled without driver involvement. Who is correct?

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

Question 14

Technician A says a transfer case may have a limited-slip, viscous-type clutch assembly. Technician B says a transfer case may have a multiple plate clutch assembly for limited slip. Who is correct?

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

Question 15

The purpose of the interaxle differential is to compensate for differences in front-wheel and rear-wheel speeds such as when turning a corner.

Question 16

Most full-time AWD systems give the driver the option of 2WD or 4WD.

Question 17

Many late-model vehicles with 4WD systems have the ability to automatically switch from 2WD to 4WD.

Question 18

Shifting between _____ can be done at a stop or while driving at any speed.

A) 4WD-Auto and 4WD-High
B) 4WD-High and 4WD-Low
C) 4WD-Low and 4WD-Auto
D) 4WD-Low and 4WD-High

Question 19

Integrated full-time 4WD systems use _____ controls to enhance full-time operation.

A) manual
B) automatic
C) computer
D) paddle

Question 20

A 4WD vehicle are designed to operate optimally in 4WD-High and 4WD-Low on any road or off-road condition.

Question 21

Provide a brief overview of the components associated with Mitsubishi? 's Super All Wheel Control (S-AWC) system?

Question 22

What are the two advantages claimed by AWD Subarus as a result of sending 90 percent of the engine's power to the front wheels?

Question 23

How are on-demand 4WD systems controlled?

Question 24

What is a viscous transmission?

Question 25

List and briefly describe the most common 4WD operational modes.

Question 26

What does the acronym VTM-4 stand for?

Question 27

When the transfer case is in the lock position, the vehicle should be _____.

A) on dry pavement
B) traveling at highway speeds
C) on a limited traction surface
D) completely stopped

Question 28

Clutches, viscous couplings, Torsen, and Quaife differentials are used in place of the differential in what types of vehicles.

Question 29

What is the difference between 4WD and AWD systems?

Question 30

A _____ is a geared, torque-sensitive mechanical limited-slip differential that uses worm gears to "sense" torque on one shaft.

A) Haldex
B) Torsen
C) Quaife differential
D) Control Trac II

Question 31

Technician A says electronically controlled systems may use sensor inputs to control the center differential for front-rear torque bias. Technician B says the Porsche PTM system uses an electronically controlled motor in the transfer case. Who is correct?

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

Question 32

In addition to preventing wheel slip, what other conditions are eliminated by the BMW xDrive system?

Question 33

Electronically controlled valves, hydraulic pumps, and wet clutches are components found in a(n) _____.

A) Haldex clutch
B) Torsen unit
C) Quaife differential
D) Control Trac II

Question 34

An open differential sends power to which axle?

Question 35

Explain the difference between full-time and part-time four-wheel drive.

Question 36

Technician A says the Haldex clutch uses hydraulic pressure to regulate torque between the front and rear axles. Technician B says the Quaife differential uses clutches to regulate torque between front and rear axles. Who is correct?

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

Question 37

A viscous coupling differential sends power to which axle?

Question 38

What type of fluid is used in a viscous coupling case?

Question 39

Name the main components of a typical viscous coupling labeled in the figure below.

Question 40

How does the Honda/Acura VTM-4 system control torque for the rear differential?