In a power-split hybrid transaxle, the engine drives the planet carrier of a planetary gear set, motor-generator 1 (MG1) drives the sun gear, and the ring gear turns with motor-generator 2 (MG2) and the wheels. It has no clutches, bands or torque converter. How does the system change engine speed at a given road speed?

By changing the speed of MG1 at the sun gear

By moving the pulley sheaves that drive a steel belt

By changing the speed of MG2 at the ring gear

By changing the ratio of the final drive gears

An automatic transaxle loses drive for a moment, with the engine speed flaring, during hard turns and hard stops. It drives normally in a straight line, under full throttle and on long climbs, and no DTCs are stored. Which of these could be the cause?

A level low enough to uncover the filter pickup

A one-way clutch that fails to hold in first gear

A forward clutch worn enough to slip under load

A converter clutch that stays applied at stops

A shift solenoid circuit DTC had turned on the MIL. After the wiring was repaired, the technician cleared the DTCs with the scan tool and the MIL went out, but the scan tool still lists a permanent DTC for that circuit, with no pending or confirmed DTCs stored. What should the technician do?

Drive until the circuit test runs and passes

Disconnect the battery to erase the code

Replace the TCM, since the code will not clear

Rediagnose the circuit, as the fault is present

A lock-up converter is controlled through two passages: one feeds fluid between the TCC piston and the converter cover, the other feeds the turbine side of the piston. How is the TCC applied?

Fluid between piston and cover is exhausted

Fluid on the turbine side is exhausted

Fluid is fed between the piston and cover

Fluid flow through the converter is stopped

Why are the CAN high and CAN low wires that run to a TCM twisted around each other along the harness?

So outside noise affects both wires equally

So the two wires stay exactly the same length

So the pair can carry more current to the TCM

So each wire shields the other from engine heat

With second gear commanded at a steady 30 mph, the scan tool shows input (turbine) speed 2,950 rpm and output speed 1,000 rpm; the output speed agrees with the vehicle speed from the ABS module. The manufacturer lists the gear ratios as first 2.95:1, second 1.62:1 and third 1.00:1. What do these readings show?

The transmission is still in first gear.

The transmission is in second gear.

The transmission is slipping in second gear.

The output speed sensor is reading low.

Why must the shift linkage be adjusted so the transmission's manual lever sits fully in its detent in each position of the shifter?

So the manual valve lines up with its passages

So throttle pressure follows the accelerator pedal

So the TCC can apply once the top gear is reached

So the pump puts out more volume in the low ranges

During a valve body inspection, a check ball is found in a pocket where it seats against a single hole. What does a check ball fitted this way do?

Lets fluid flow through the hole one way only

Catches debris before it reaches the solenoids

Meters fluid through a fixed hole to time shifts

Holds line pressure at its regulated value

A servo cover sits in its bore under the force of the servo return spring and is held in by a snap ring. Why is a cover compressor tool used to push the cover down before the snap ring is removed?

To take the spring's load off the snap ring

To check the return spring's installed height

To keep fluid from draining out of the bore

To break the cover's seal free from its bore

A transmission's front pump seal has been replaced twice in 12,000 miles. Each time, the old seal's lip was worn through, and the pump bushing is now worn loose on the converter hub. Any of these could be the cause EXCEPT:

line pressure above the manufacturer's specification.

a burr holding one side of the case off the block.

converter hub runout beyond the manufacturer's limit.

10 Free ASE A2 Automatic Transmission/Transaxle Questions

Ten ASE A2 Automatic Transmission/Transaxle questions in the ASE format: four options, one best answer. They are free to use, print and share, and there is nothing to sign up for on this page.

01How to use these

The questions come from the ToolboxPrep A2 bank and are spread across the test's content areas in the proportion the ASE test specification gives them: A (Transmission/Transaxle Diagnosis), B (In-Vehicle Transmission/Transaxle Maintenance and Repair), C (Transmission/Transaxle Unit Removal, Inspection, and Installation). Answer each one before opening the explanation. Every explanation covers all four options, because knowing why the wrong answers are wrong is most of the skill.

Pace. The A2 test gives you 75 minutes for 55 questions (45 scored, 10 unscored), about 1 min 22 s a question. Try these at that pace.
Print. The printed version shows the questions and the answer key without the explanations, so it works as a handout.

02The questions

Recall · Transmission/Transaxle Diagnosis

In a power-split hybrid transaxle, the engine drives the planet carrier of a planetary gear set, motor-generator 1 (MG1) drives the sun gear, and the ring gear turns with motor-generator 2 (MG2) and the wheels. It has no clutches, bands or torque converter. How does the system change engine speed at a given road speed?
1. By moving the pulley sheaves that drive a steel belt
2. By changing the speed of MG2 at the ring gear
3. By changing the speed of MG1 at the sun gear
4. By changing the ratio of the final drive gears
Show the answer

C. Correct. With the ring gear's speed set by road speed, the carrier's speed, which is engine speed, depends on how fast the sun gear turns, so the system speeds MG1 up or slows it down to set engine speed. That is why this layout acts as an electronically controlled continuously variable transmission.

Why not the others

A. Moving pulley sheaves on a steel belt is how a belt-and-pulley CVT works. This transaxle has no belt or pulleys; its continuously variable action comes from controlling MG1's speed at the sun gear.

B. MG2 turns with the ring gear and the wheels, so its speed is fixed by road speed and cannot be changed at a given road speed. Engine speed is set through the sun gear, by MG1.

D. The final drive gears have one fixed ratio. Engine speed at a given road speed is varied by controlling MG1's speed at the sun gear.
Diagnosis · Transmission/Transaxle Diagnosis

An automatic transaxle loses drive for a moment, with the engine speed flaring, during hard turns and hard stops. It drives normally in a straight line, under full throttle and on long climbs, and no DTCs are stored. Which of these could be the cause?
1. A one-way clutch that fails to hold in first gear
2. A forward clutch worn enough to slip under load
3. A converter clutch that stays applied at stops
4. A level low enough to uncover the filter pickup
Show the answer

D. Correct. When the fluid is low, it surges away from the filter pickup in hard turns and stops, the pump draws air, and line pressure drops long enough for a clutch to slip. Normal drive at full throttle and on climbs, when the fluid stays over the pickup, fits that pattern; the next step is to check the level by the manufacturer's procedure.

Why not the others

A. A one-way clutch that does not hold in first gear slips on every launch from a stop, including under full throttle. Here full-throttle driving is normal and the slips follow fluid sloshing, which points to a low level.

B. A worn forward clutch slips most under the heaviest torque, so full-throttle starts and long climbs would show it. Those are normal here; slips that come only with fluid sloshing in turns and stops point to a low level.

C. A converter clutch that stays applied at a stop drags the engine down, so it stumbles or stalls; it does not flare. The momentary flare in turns and stops points to the pump drawing air from a low level.
Diagnosis · Transmission/Transaxle Diagnosis

A shift solenoid circuit DTC had turned on the MIL. After the wiring was repaired, the technician cleared the DTCs with the scan tool and the MIL went out, but the scan tool still lists a permanent DTC for that circuit, with no pending or confirmed DTCs stored. What should the technician do?
1. Disconnect the battery to erase the code
2. Drive until the circuit test runs and passes
3. Replace the TCM, since the code will not clear
4. Rediagnose the circuit, as the fault is present
Show the answer

B. Correct. A permanent DTC cannot be erased with a scan tool or by disconnecting the battery; the module erases it itself after the diagnostic that set it has run and found no fault on a qualifying drive. Driving under that test's enable criteria and rescanning confirms the repair and lets the permanent DTC clear.

Why not the others

A. A permanent DTC is stored so that it survives a battery disconnect as well as a scan-tool clear, so disconnecting the battery leaves it in place. The module erases it itself once the test that set it runs and passes on a drive.

C. Nothing points to the TCM: a permanent DTC that stays after a clear is how the system is designed to work until the test that set it runs and passes. Driving to run that test lets the module erase it.

D. With no pending or confirmed DTC after the clear, nothing shows the fault is present now; a permanent DTC stays until its test runs and passes. If the test fails on the drive, a pending DTC sets and diagnosis continues then.
Recall · Transmission/Transaxle Diagnosis

A lock-up converter is controlled through two passages: one feeds fluid between the TCC piston and the converter cover, the other feeds the turbine side of the piston. How is the TCC applied?
1. Fluid on the turbine side is exhausted
2. Fluid is fed between the piston and cover
3. Fluid between piston and cover is exhausted
4. Fluid flow through the converter is stopped
Show the answer

C. Correct. When the passage between the piston and the cover is opened to exhaust, converter pressure on the turbine side pushes the piston against the cover and locks the turbine to the engine. Feeding that passage again pushes the piston away and releases the clutch.

Why not the others

A. The turbine side is the side whose pressure does the pushing; exhausting it would remove the apply force. Apply comes from exhausting the passage between the piston and the cover.

B. Feeding fluid between the piston and the cover pushes the piston away from the cover; that is the release condition. Apply comes from exhausting that passage.

D. The converter stays charged with fluid in both states; only the direction of the pressure difference across the piston changes. Apply comes from exhausting the passage between the piston and the cover.
Recall · Transmission/Transaxle Diagnosis

Why are the CAN high and CAN low wires that run to a TCM twisted around each other along the harness?
1. So the two wires stay exactly the same length
2. So outside noise affects both wires equally
3. So the pair can carry more current to the TCM
4. So each wire shields the other from engine heat
Show the answer

B. Correct. The modules read the difference in voltage between CAN high and CAN low, so noise picked up equally by both twisted wires cancels out. A wiring repair keeps the twist as close to the original as it can for the same reason.

Why not the others

A. Matching the lengths is not the purpose; two wires laid side by side would be the same length too. The twist makes any induced noise equal on both wires, so it cancels when the modules read the difference between them.

C. The bus carries small signal currents, and twisting does not change a wire's current capacity. The twist exists so outside noise is picked up equally by both wires and cancels in the difference signal.

D. Twisting gives no protection from heat; that comes from routing, sleeving and heat shields. The twist makes induced noise equal on both wires so the receiving modules can cancel it.
Spec reading · Transmission/Transaxle Diagnosis

With second gear commanded at a steady 30 mph, the scan tool shows input (turbine) speed 2,950 rpm and output speed 1,000 rpm; the output speed agrees with the vehicle speed from the ABS module. The manufacturer lists the gear ratios as first 2.95:1, second 1.62:1 and third 1.00:1. What do these readings show?
1. The transmission is in second gear.
2. The transmission is still in first gear.
3. The transmission is slipping in second gear.
4. The output speed sensor is reading low.
Show the answer

B. Correct. 2,950 ÷ 1,000 = 2.95, exactly the first-gear ratio, so the transmission never left first even though second is commanded. Whatever applies second gear (its shift solenoid circuit, valve, or the second-gear clutch or band) is diagnosed next.

Why not the others

A. Second gear would need an input speed of 1,000 × 1.62 = 1,620 rpm. The measured 2,950 rpm divided by 1,000 rpm is 2.95, the first-gear ratio.

C. Slip in second would give an input speed above 1,620 rpm that wanders with load, not a steady ratio that exactly matches first. A steady 2.95:1 ratio means first gear is still in.

D. The output speed agrees with the vehicle speed from the ABS module, so the sensor reads correctly. The 2.95:1 ratio of input to output speed shows the transmission is still in first.
Recall · In-Vehicle Transmission/Transaxle Maintenance and Repair

Why must the shift linkage be adjusted so the transmission's manual lever sits fully in its detent in each position of the shifter?
1. So throttle pressure follows the accelerator pedal
2. So the TCC can apply once the top gear is reached
3. So the manual valve lines up with its passages
4. So the pump puts out more volume in the low ranges
Show the answer

C. Correct. The manual lever positions the manual valve in the valve body, and that valve sends line pressure to the circuits for the selected range. A lever resting between detents leaves the valve part-way, which can restrict feed to an apply circuit and cause delayed engagement, slipping and clutch wear.

Why not the others

A. Throttle pressure comes from a separate throttle valve cable on older units and from a pressure control solenoid on electronic units; the shift linkage does not set it. The detent places the manual valve so it fully opens the selected range's circuits.

B. The TCC applies when the control module commands its solenoid under the right speed, load and temperature conditions; the lever's detent does not decide that. The detent matters because it places the manual valve squarely over the passages for the selected range.

D. Pump output rises with engine speed (and on a variable-displacement pump is trimmed by the pressure regulator's signal); the shift lever's position does not change it. The detent matters because it locates the manual valve over the passages for the selected range.
Recall · In-Vehicle Transmission/Transaxle Maintenance and Repair

During a valve body inspection, a check ball is found in a pocket where it seats against a single hole. What does a check ball fitted this way do?
1. Catches debris before it reaches the solenoids
2. Meters fluid through a fixed hole to time shifts
3. Lets fluid flow through the hole one way only
4. Holds line pressure at its regulated value
Show the answer

C. Correct. Pressure from one side lifts the ball off the hole and lets fluid pass, while pressure from the other side seats it and blocks the flow, so the ball acts as a one-way valve for that circuit. A ball left out or put in the wrong pocket changes how a circuit fills or exhausts, which can show up as a harsh or soft shift.

Why not the others

A. Debris is caught by the filter and, on many units, by screens at the solenoid feeds, not by check balls. A ball seated on a hole works as a one-way valve.

B. A fixed restriction that times a shift is an orifice in the spacer plate; the ball itself does not meter flow. A ball seated on a hole lets fluid through in one direction only.

D. Line pressure is held by the pressure regulator valve, under control of a pressure control solenoid on electronic units. A check ball on a hole lets fluid flow one way only.
Recall · In-Vehicle Transmission/Transaxle Maintenance and Repair

A servo cover sits in its bore under the force of the servo return spring and is held in by a snap ring. Why is a cover compressor tool used to push the cover down before the snap ring is removed?
1. To take the spring's load off the snap ring
2. To check the return spring's installed height
3. To keep fluid from draining out of the bore
4. To break the cover's seal free from its bore
Show the answer

A. Correct. The return spring pushes the cover hard against the snap ring, so the ring is under load; pressing the cover in with the tool unloads the ring so it can be removed, then lets the cover rise under control instead of springing out. The same tool compresses the cover again to fit the ring on reassembly.

Why not the others

B. The tool only pushes the cover down; it does not measure anything. Spring condition is checked out of the bore against the manufacturer's free length or load figures.

C. Fluid behind the cover runs out when the cover comes off, whatever tool is used. The tool's job is to take the spring load off the snap ring.

D. Pushing the cover farther into its bore does not free its seal; the seal comes out with the cover once the snap ring is off. The tool takes the spring load off the ring.
EXCEPT · Transmission/Transaxle Unit Removal, Inspection, and Installation

A transmission's front pump seal has been replaced twice in 12,000 miles. Each time, the old seal's lip was worn through, and the pump bushing is now worn loose on the converter hub. Any of these could be the cause EXCEPT:
1. a burr holding one side of the case off the block.
2. a worn crankshaft pilot bore.
3. converter hub runout beyond the manufacturer's limit.
4. line pressure above the manufacturer's specification.
Show the answer

D. Correct. Line pressure is hydraulic: it does not push the converter hub off center or make it wobble, so it cannot wear the bushing loose or wear through the seal lip. Repeated seal wear with a worn-loose bushing means the hub is not running true in the bushing, so the converter's alignment and hub runout are checked before a third seal goes in.

Why not the others

A. This could cause it. A burr or debris on the mating face cocks the case on the block, so the pump bore no longer lines up with the crankshaft and the converter hub runs off-center in the bushing and seal. Mating faces are cleaned and checked before the case is bolted up.

B. This could cause it. The converter's pilot centers its front end in the crankshaft; a worn bore lets that end run off-center, so the hub rides hard on the pump bushing and seal and wears both.

C. This could cause it. A hub that runs out swings around inside the pump bushing every revolution, wearing the bushing loose and working the seal lip, which is why hub runout is checked with a dial indicator against the manufacturer's limit.

03Answer key

Question	Answer	Content area
Q1	C	Transmission/Transaxle Diagnosis
Q2	D	Transmission/Transaxle Diagnosis
Q3	B	Transmission/Transaxle Diagnosis
Q4	C	Transmission/Transaxle Diagnosis
Q5	B	Transmission/Transaxle Diagnosis
Q6	B	Transmission/Transaxle Diagnosis
Q7	C	In-Vehicle Transmission/Transaxle Maintenance and Repair
Q8	C	In-Vehicle Transmission/Transaxle Maintenance and Repair
Q9	A	In-Vehicle Transmission/Transaxle Maintenance and Repair
Q10	D	Transmission/Transaxle Unit Removal, Inspection, and Installation

04Questions by content area

Working on one part of the A2 test? Each content area has its own page with five more free questions.

05More free questions

The A2 study guide covers each content area and how to study for it, and the ASE A2 Automatic Transmission/Transaxle practice test page describes the full A2 question bank. The same free format is available for the other eight tests.

How these questions are written and checked: how our questions are made. Found a mistake? Tell us and we will fix it.

ToolboxPrep is an independent study site. It is not affiliated with or endorsed by ASE (the National Institute for Automotive Service Excellence). Our questions are original practice questions written to the published ASE test specifications; they are not actual test questions.