Deck 42: Electronic Automatic Transmissions

Question 1

In a vehicle with a dual mode transmission, during normal driving under light loads, the vehicle is driven solely by the engine.

Answer 1

True

Question 2

To test a solenoid with an ohmmeter, the transmission pan must be removed.

Answer 2

False

Question 3

The _____ is a voltage generating sensor that uses a Hall effect or PM generator to produce a signal.

A) VSS (vehicle speed sensor)
B) OSS (output shaft speed)
C) TSS (turbine shaft speed)
D) all answers are correct

Answer 3

D

Question 4

On the Toyota/Lexus automatic transmissions with manual control, drivers must exercise caution when manually shifting to prevent engine or transmission failure.

Question 5

The EPC (electronic pressure control) solenoid is duty-cycle-controlled by the TCM.

Question 6

The Toyota/Lexus hybrid is driven by MG1 when running solely on electric power.

Question 7

Which of the following is NOT an advantage of an electronically controlled transmission?

A) higher torque capacity
B) improved fuel economy
C) lower exhaust emission levels
D) better shift timing

Question 8

Shift, pressure control, and T/C clutch solenoids are usually located on the ______.

A) outside of the transmission case
B) valve body
C) extension housing
D) bellhousing

Question 9

Which of the following statements concerning the operating characteristics of an EAT during limp-in mode is NOT true?

A) The transmission locks in third gear when the gear selector is in the Drive position or second gear when it is in a lower position
B) The transmission will remain locked in fourth gear when in Drive
C) The transmission will operate only in Park, Neutral, Reverse, and Second gears and will not upshift or downshift
D) The transmission will remain in whatever gear it was in but will shift into third or second gear and stay there as soon as the vehicle slows down

Question 10

A _____ contains the actual shift points to be used by the computer according to the input data it receives from the sensors.

A) solenoid driver
B) shift schedule
C) turbine speed sensor
D) logic controller

Question 11

If the crankshaft speed sensor reads 1,650 rpm and the TSS (turbine speed sensor) also reads 1,650 RPM, the torque converter is ______.

A) overheating
B) in a stall condition
C) slipping
D) coupled

Question 12

The EPC solenoid provides changes in pressure in response to engine load.

Question 13

Two technicians are discussing EPC solenoids. Technician A says the EPC solenoid is a PWW (pulse width modulated) solenoid and receives a duty cycle signal from the TCM. Technician B says the EPC solenoid is an on/off solenoid that is turned on when the TCM sees the 3-4 upshift. Who is correct?

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

Question 14

TV-tuner cleaning spray is a good solvent to use for cleaning electrical terminals and connectors.

Question 15

Which of the following is NOT a TCM input signal?

A) TP (throttle position)
B) ECT (engine coolant temperature)
C) MAP (manifold absolute pressure)
D) TCC-DC (torque converter clutch-duty cycle)

Question 16

Transmission solenoids shift gears by mechanically coupling gears to the output shaft.

Question 17

When transmission fluid temperature is too high, the TCM will cause the transmission to ______.

A) shift sooner than normal
B) shift later than normal
C) not upshift into high gear
D) stay locked in high gear

Question 18

PCM input data such as MAP, TP, and engine speed cannot be transferred to the TCM through the vehicle CAN bus.

Question 19

A DTC for an input signal that is too low or too high can be caused by an internal transmission mechanical or hydraulic failure.

Question 20

The TFT sensor is a _____ and its output signal varies with ATF temperature.

A) thermistor
B) thermal relay
C) Hall-effect switch
D) bi-metal relay

Question 21

The customer complains of shudder that occurs at light throttle just when the vehicle reaches 45 mph. The shudder lasts for a few seconds then stops until the vehicle slows down and then speeds back up to 45 mph. The problem could be ______.

A) a fouled spark plug
B) an arcing ignition wire
C) a broken transmission mount
D) a defective TCC solenoid

Question 22

The first step in diagnosing an EAT transmission problem is ______.

A) connect a scan tool and read DTCs
B) connect a pressure gauge to the transmission and record line pressure
C) manually activate shift solenoids with a jumper wire or transmission tester
D) check the adjustment of the TV [throttle valve] cable

Question 23

Technician A measures sensors only when they are cold. Technician B uses dielectric grease on electrical connections to prevent corrosion. Who is correct?

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

Question 24

Two technicians are discussing the operation of the Toyota/Lexus hybrid transaxle. Technician A says that the vehicle is driven electrically by MG2 when the transmission selector is in reverse. Technician B says that whenever the car is powered by MG2, the engine may start if the battery SOC is low. Who is correct?

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

Question 25

The application of the TCC [torque converter clutch] is controlled by the ______.

A) TCC solenoid
B) MAF sensor
C) MAP sensor
D) all answers are correct

Question 26

Air pressure can be used to test _____.

A) turbine speed sensors
B) transmission gear range switches
C) vehicle speed sensors
D) pressure switches

Question 27

"Input split" and "compound split" are two modes of operation in a _____type transmission.

A) conventional CVT [Honda]
B) dual-mode hybrid
C) hybrid electronic CVT [Toyota/Lexus]
D) conventional planetary

Question 28

What type of sensor listed here is a potentiometer?

A) pressure switch
B) TFT sensor [transmission fluid temperature]
C) TSS [turbine speed sensor]
D) TP [throttle position]

Question 29

A computer-controlled transmission that starts out in the wrong gear could be caused by ______.

A) faulty solenoids
B) stuck valves
C) bad electrical grounds
D) all answers are correct

Question 30

The Toyota/Lexus hybrid transaxle uses a _________________ that combines the power from the gasoline engine with the power from the electric motors.

A) multiple disc clutch
B) torque converter
C) differential
D) planetary gearset

Question 31

When testing a solenoid with an ohmmeter, an infinite reading across the solenoid coil indicates that ______.

A) the coil is shorted between windings
B) the coil is shorted to ground
C) the coil is open
D) this is a normal reading for a solenoid coil

Question 32

In the Toyota/Lexus hybrid transaxle, the engine output is coupled to what component of the planetary gearset?

A) sun
B) carrier
C) ring
D) the engine is not directly coupled to any of the planetary gears

Question 33

Two technicians are discussing CVT transmissions. Technician A says that when a CVT-equipped car is accelerating, the engine RPM remains constant as the mph increases. Technician B says that some CVT vehicles do not have torque converters. They use a multiple disc starting clutch for idling and starting from a dead stop.

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

Question 34

A magnetic pulse generator [PM generator] type sensor is commonly used to measure _____ on an EAT transmission.

A) speed [rpm]
B) temperature
C) pressure
D) all answers are correct

Question 35

The dual mode hybrid transmission contains all the following components EXCEPT:

A) two electric motors
B) three sets of planetary gears
C) multiple disc clutches
D) a metal drive belt and variable pulleys

Question 36

Two technicians are testing a transmission that has a DTC for a shift solenoid. The coil resistance is within specifications and the solenoid clicks when the coil is energized with jumper wires. Technician A says the solenoid could be leaking internally or externally. Technician B says the valve within the solenoid could be sticking or binding. Who is correct?

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

Question 37

Which of the following is NOT a component of the Toyota/Lexus hybrid transaxle?

A) motor/generators 1 and 2
B) planetary gear set
C) multiple disc clutch
D) differential assembly

Question 38

Which of the following tools is NOT used to check a TP sensor?

A) voltmeter
B) ammeter
C) ohmmeter
D) lab scope

Question 39

When a Toyota/Lexus hybrid vehicle is operating under heavy loads, ______.

A) the engine is providing power
B) MG1 is providing power
C) MG2 is providing power
D) all answers are correct

Question 40

When a Toyota/Lexus hybrid is driving on electric power, if more torque is needed, _____ is activated to start the engine.

A) MG1
B) MG2
C) 12-volt DC starter
D) all answers are correct

Question 41

Name four input sensors that supply information to the TCM [transmission control module] through the network bus.

Question 42

How does a pressure control solenoid regulate transmission pressures?

Question 43

What happens when the transmission mode switch is set to Power?

Question 44

A homemade tester for checking the operation of the ____________________ can easily be made from an old wiring harness and a few simple switches.

Question 45

Name two TCM outputs.

Question 46

Name three input sensors that connect directly to the TCM. These sensors are generally mounted on or inside the transmission.

Question 47

Hydraulically controlled transmissions rely on signals from the ____________________ and ____________________ to force a shift in gears.

Question 48

The TCM is programmed to adjust its operating parameters in response to changes within the system, such as component wear. As component wear and shift overlap times increase, the TCM adjusts line pressure to maintain proper shift timing calibrations. This is called ____________________.

Question 49

How does a pulse width modulated solenoid control transmission pressure?

Question 50

If the TCM loses source voltage, the transmission will enter into ____________________ mode.

Question 51

How do you diagnose a problem with an electronically controlled transmission that does not set a DTC?

Question 52

Describe what happens when the transmission goes into limp-in mode.

Question 53

An ____________________ converts analog AC signals into digital DC square waves.

Question 54

Normally, the shift solenoids receive voltage through the ignition switch and are grounded through the ____________________.

Question 55

The Honda CVT transmission does not have a torque converter. Honda uses a ____________________ to get the car moving without stalling or straining the engine.

Question 56

The MAP sensor is connected to the PCM. The TCM gets manifold pressure information from the PCM through ____________________.

Question 57

Toyota, Ford, and Nissan hybrid systems rely on ____________________ to determine the overall gear ratio of their CVTs.

Question 58

What is the function of the start clutch in the Honda CVT transaxle?

Question 59

The ____________________ sensor on an EAT replaces the governor used on a hydraulic-controlled transmission.

Question 60

How does adaptive learning improve the shift quality of an electronically controlled transmission?