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ASE A2 practice questions

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Question 1General Transmission and Transaxle Diagnosis

When checking automatic transmission fluid level with a dipstick, the engine should be:

  1. off and the fluid cold
  2. running, at operating temperature, in park or neutral Correct answer.
  3. off, after the vehicle has been driven at highway speed
  4. running at fast idle with the selector in drive

Explanation

Fluid level is checked with the engine running, at normal operating temperature, and the selector in park or neutral so the pump is running and the converter and cooler are filled. Checking with the engine off or cold gives a false low reading on most units.

Question 2General Transmission and Transaxle Diagnosis

Dark, burned-smelling automatic transmission fluid most often indicates:

  1. overheated clutch or band friction material Correct answer.
  2. normal fluid breakdown after a long service interval
  3. a cooler bypass valve stuck open
  4. an overfilled transmission

Explanation

Friction material that has been overheated breaks down and discolors the fluid while producing a characteristic burned odor. The fluid condition is used as evidence of internal heat and slip, not simply of time in service.

Question 3General Transmission and Transaxle Diagnosis

A customer complains that the transmission shifts harshly. The technician's first step should be to:

  1. overhaul the transmission and replace the converter
  2. replace the fluid and filter as a first attempt
  3. remove the valve body and inspect the valves and springs
  4. verify the concern and check for stored codes Correct answer.

Explanation

Diagnosis begins with confirming the customer's complaint and gathering information from the control system before any parts are removed. Stored codes and scan tool data often point directly to an electrical or input-signal cause of harsh shifts.

Question 4General Transmission and Transaxle Diagnosis

Adding ultraviolet dye to the transmission fluid helps locate leaks because the dye:

  1. seals the leak so it can be identified later
  2. thickens the fluid so small leaks stop
  3. changes color when the fluid overheats
  4. fluoresces under a black light at the leak Correct answer.

Explanation

The dye is carried with the fluid and glows brightly where fluid escapes and collects, making a small seep visible under ultraviolet light. It does not change the fluid's sealing, viscosity, or temperature behavior.

Question 5General Transmission and Transaxle Diagnosis

An ohmmeter reading across the terminals of a shift solenoid is within the manufacturer's specification. This test confirms that:

  1. the coil is intact but the valve may still stick Correct answer.
  2. the solenoid will work correctly in every operating condition
  3. the solenoid is shorted to ground
  4. the driver circuit in the TCM is good

Explanation

Resistance testing only proves the winding is continuous and in range. It cannot detect a mechanically stuck valve, a contaminated solenoid, or a fault in the wiring or driver that feeds it.

Question 6General Transmission and Transaxle Diagnosis

When topping off an automatic transmission, the correct fluid to use is the one:

  1. that matches the color of the fluid already in the unit
  2. with the highest viscosity on the shelf
  3. listed by the manufacturer for that transmission Correct answer.
  4. made for the newest model year

Explanation

Fluid requirements are set by the transmission's friction, seal, and hydraulic design, so the manufacturer's specification for that exact unit must be used. Color and viscosity alone do not identify a fluid as suitable.

Question 7General Transmission and Transaxle Diagnosis

During a stall test, engine speed is above specification in both drive and reverse. Which of these is the most likely cause?

  1. a restricted transmission cooler
  2. low line pressure or slipping clutches Correct answer.
  3. a dragging parking brake
  4. an engine with low power, such as a restricted exhaust

Explanation

A stall test loads the engine against a stationary output, so a stall speed higher than specification means something in the drive path is slipping. Low line pressure, worn apply components, or a failed converter stator one-way clutch all raise stall speed. A stall speed below specification points to an engine power problem or a restricted exhaust.

Question 8General Transmission and Transaxle Diagnosis

Line pressure is below specification at idle and does not rise when the throttle is opened during a pressure test. The technician should suspect:

  1. a worn pump or a stuck pressure regulator Correct answer.
  2. a manual valve that is misadjusted
  3. a faulty output shaft speed sensor
  4. a torque converter clutch that is slipping under load

Explanation

Line pressure is produced by the pump and regulated by the pressure regulator valve in response to throttle signal. A reading that is low and does not respond to throttle indicates the pump is not delivering volume or the regulator is dumping pressure, and a low fluid level can produce the same result.

Question 9General Transmission and Transaxle Diagnosis

The TCM sets a code for an incorrect gear ratio in second gear only; ratios in first, third, and fourth are correct. The most likely cause is:

  1. a torque converter clutch that stays applied
  2. a faulty turbine speed sensor
  3. a faulty output speed sensor
  4. slippage in the second gear apply circuit Correct answer.

Explanation

The TCM calculates ratio by comparing input and output speed signals for the commanded gear. If other gears calculate correctly, both sensors and their wiring must be good, so a ratio error limited to one gear points to slip in that gear's apply circuit.

Question 10General Transmission and Transaxle Diagnosis

On a transmission that uses a throttle valve cable, a cable adjusted too tight will cause:

  1. early, soft shifts and lower line pressure at light throttle
  2. later, firmer shifts and higher line pressure Correct answer.
  3. no engagement in reverse
  4. converter clutch shudder at cruise

Explanation

The throttle valve cable transmits throttle position to the transmission so it can schedule line pressure and shift points. A cable that is too tight makes the transmission read more throttle than actually exists, which raises line pressure and delays and firms shifts.

Question 11General Transmission and Transaxle Diagnosis

A transmission with a vacuum modulator shifts harshly at all throttle positions, and transmission fluid is found in the modulator's vacuum hose. The most likely cause is:

  1. a misadjusted throttle valve cable
  2. a ruptured modulator diaphragm Correct answer.
  3. a low fluid level
  4. a restricted exhaust system

Explanation

The modulator uses engine vacuum to reduce line pressure as vacuum rises. Fluid in the vacuum hose proves the diaphragm has failed, so the modulator delivers no vacuum signal, pressure stays high, and shifts are harsh at every throttle opening.

Question 12General Transmission and Transaxle Diagnosis

A vehicle has a vibration at light throttle between 45 and 55 mph. The vibration disappears when the torque converter clutch is commanded off with a scan tool. The most likely cause is:

  1. a failing output shaft bearing
  2. an out-of-balance tire or a bent wheel rim
  3. a worn outer CV joint
  4. a shuddering torque converter clutch Correct answer.

Explanation

If releasing the converter clutch removes the vibration, the disturbance is coming from the clutch apply path. Worn lining, a scored cover, or contaminated fluid causes the clutch to grab and release, which is felt as a shudder during light-throttle cruise.

Question 13General Transmission and Transaxle Diagnosis

After sitting overnight, a vehicle takes several seconds to engage drive; after the first engagement of the day it engages normally. The most likely cause is:

  1. a restricted cooler or kinked cooler line
  2. a faulty park/neutral switch
  3. converter drain-back past a leaking check valve Correct answer.
  4. worn forward clutch plates

Explanation

If the converter drains back while the vehicle sits, the pump must refill it before the apply circuit can build pressure, so only the first engagement of the day is slow. A leaking check valve, a worn pump, or an internal leak are common sources of drain-back.

Question 14General Transmission and Transaxle Diagnosis

An air pressure test is being performed with the valve body removed. Its purpose is to:

  1. measure the line pressure available at the servo piston
  2. check torque converter clutch lockup
  3. confirm that clutch and band circuits apply and hold Correct answer.
  4. verify solenoid resistance with a meter

Explanation

With the valve body off, shop air is fed into individual passages to confirm that each clutch or band piston strokes and that its seals hold pressure. It is a mechanical integrity test, not a pressure measurement or an electrical test.

Question 15General Transmission and Transaxle Diagnosis

A vehicle will not crank in park but cranks in neutral, and the scan tool shows PARK when the lever is in neutral. The most likely cause is:

  1. a misadjusted range sensor Correct answer.
  2. a starter motor with worn brushes
  3. a battery that is discharged
  4. a defective starter solenoid

Explanation

The range sensor reports lever position to both the TCM and the starter inhibit circuit. When the scan tool shows a range that does not match the lever, the sensor or its adjustment is wrong and the wrong position is being reported to the start circuit.

Question 16General Transmission and Transaxle Diagnosis

Which of these is most likely to cause automatic transmission fluid to overheat during normal driving?

  1. a restricted cooler or a failing cooling fan Correct answer.
  2. an overcharged air conditioning system
  3. a torque converter clutch that locks up normally
  4. a thermostat that opens late

Explanation

Most transmission heat is generated in the converter and removed through the cooler circuit. A restricted cooler or a fan that does not run removes less heat, so fluid temperature climbs during ordinary driving even though the transmission itself is not slipping.

Question 17General Transmission and Transaxle Diagnosis

A vehicle does not move in any gear. Before removing the transmission, the technician should first:

  1. replace the torque converter
  2. replace the range sensor and reset adaptations
  3. check the fluid level and shift linkage Correct answer.
  4. rebuild the valve body

Explanation

A no-movement complaint can come from a low fluid level or a disconnected shifter cable rather than an internal failure. These quick external checks must be completed before the unit is removed.

Question 18General Transmission and Transaxle Diagnosis

A transmission slips in all forward gears but reverse works normally. Which component is the most likely cause?

  1. the reverse input clutch
  2. the output shaft speed sensor
  3. the forward clutch Correct answer.
  4. the low/reverse band

Explanation

The forward clutch is applied in every forward range, so a failed forward clutch causes slip or no movement in all forward gears. Reverse uses the reverse clutch and low/reverse band, so it continues to work.

Question 19General Transmission and Transaxle Diagnosis

A vehicle has a vibration felt only when it is stopped with the selector in drive; the vibration disappears in neutral and park. The technician should suspect:

  1. a worn half-shaft CV joint
  2. a driveshaft that is out of balance
  3. a collapsed engine or transmission mount Correct answer.
  4. an unbalanced tire

Explanation

A vibration present only at a standstill in gear comes from something loaded while the driveline is stalled. Worn mounts allow engine torque to be transmitted into the body when the converter is loaded in gear. Tire, wheel, and driveshaft faults require vehicle speed to appear.

Question 20General Transmission and Transaxle Diagnosis

Which test best verifies a pulse-width-modulated shift solenoid and its circuit while it is working under load?

  1. checking for continuity to ground
  2. measuring current with an ammeter while commanding it Correct answer.
  3. measuring available voltage at the solenoid connector
  4. measuring coil resistance with an ohmmeter

Explanation

A PWM solenoid is controlled by varying current, and current flow is the best indicator that the coil and the whole circuit are working under load. Resistance and voltage checks are made with little or no current flowing and cannot show the ramp.

Question 21General Transmission and Transaxle Diagnosis

Scan tool data shows the throttle position sensor reading stuck at 4.5 volts on a vehicle with late, harsh upshifts at all throttle openings. The technician should conclude that:

  1. the fluid is burned and needs replacement
  2. the output shaft speed sensor has failed
  3. the TCM sees wide-open throttle and raises line pressure Correct answer.
  4. the transmission requires an overhaul

Explanation

Line pressure and shift points are scheduled from throttle position. A signal stuck at high voltage tells the TCM the throttle is wide open at all times, so it commands maximum line pressure and delays shifts.

Question 22General Transmission and Transaxle Diagnosis

After replacing a valve body, the technician should:

  1. disable the torque converter clutch permanently
  2. reset adaptive learning and perform a relearn drive cycle Correct answer.
  3. set the line pressure to maximum
  4. immediately return the vehicle to the customer for evaluation

Explanation

Adaptive values stored in the TCM were learned with the old valve body and no longer match the new unit. They must be cleared and relearned with the manufacturer's drive cycle, or shift quality will be poor and a comeback is likely.

Question 23General Transmission and Transaxle Diagnosis

After a transmission overhaul, the technician checks cooler flow and finds it below specification. The correct action is to:

  1. install a larger transmission pan
  2. raise line pressure to compensate for the low flow
  3. repair or replace the restricted cooler or lines Correct answer.
  4. change the fluid more often

Explanation

Cooler flow is specified to keep fluid temperature in range and to carry debris out of the unit. Low flow after a repair means the cooler or lines are restricted or kinked, and the restriction must be corrected before the vehicle is released.

Question 24General Transmission and Transaxle Diagnosis

A transmission whines in all gears, and the pitch rises and falls with road speed rather than engine speed. The most likely cause is:

  1. a worn bearing or final drive gear set Correct answer.
  2. a worn front pump that turns at engine speed
  3. a loose valve body bolt
  4. a defective torque converter

Explanation

Noise that follows road speed and is present in every gear comes from parts turning with the output, such as bearings or the final drive gear set. Pump and converter noise follow engine speed instead.

Question 25General Transmission and Transaxle Diagnosis

With a shift solenoid energized, a voltage drop of 0.8 volt is measured across its ground circuit; specification is 0.1 volt maximum. This reading indicates:

  1. the solenoid coil is open
  2. the battery is discharged
  3. excessive resistance in the ground side of the circuit Correct answer.
  4. the TCM is not commanding the solenoid at all

Explanation

Voltage drop measured while current flows shows the resistance in that part of the circuit. A drop above specification means the ground path has excessive resistance, which reduces current through the solenoid and can cause shift complaints or codes.

Question 26General Transmission and Transaxle Diagnosis

On most vehicles with a dipstick, automatic transmission fluid is checked with the engine idling and the fluid at operating temperature. The engine must be running because:

  1. the cooler bypass valve opens only at idle
  2. the pump must fill the converter and cooler Correct answer.
  3. the fluid expands only while the engine runs
  4. the TCM must be awake to read the level

Explanation

With the engine running, the transmission pump keeps the converter and cooler charged, so the level in the pan reflects true operating conditions. Checking with the engine off lets fluid drain back into the pan and produces a false high reading.

Question 27General Transmission and Transaxle Diagnosis

When performing a stall test, wide-open throttle should be held for no longer than about:

  1. 5 seconds Correct answer.
  2. 15 seconds
  3. 30 seconds
  4. 60 seconds

Explanation

At stall the converter absorbs nearly all of the engine's output and turns it into heat, with no airflow through the cooler. Limiting each run to roughly five seconds and letting the unit cool between readings keeps fluid temperature within safe limits.

Question 28General Transmission and Transaxle Diagnosis

Transmission fluid drawn from the dipstick is milky pink. The most likely cause is:

  1. engine coolant entering through the radiator cooler Correct answer.
  2. extended drain intervals using conventional fluid
  3. normal clutch material from break-in
  4. fluid that has been severely overheated

Explanation

Coolant crossing into the transmission cooler circuit mixes with ATF to form a pink emulsion. The in-tank cooler should be pressure tested and the cooling system checked for the source of the cross leak before the transmission is serviced.

Question 29General Transmission and Transaxle Diagnosis

The primary purpose of a road test during transmission diagnosis is to:

  1. warm the fluid before it is drained
  2. confirm that the converter hub seal is not leaking
  3. reproduce and evaluate the customer's complaint under load Correct answer.
  4. measure the final drive ratio with a tachometer

Explanation

Driving the vehicle under the conditions the customer describes confirms the complaint and shows which gears, speeds, and throttle angles are involved. Those observations determine which pressures and circuits are tested next.

Question 30General Transmission and Transaxle Diagnosis

ATF is dripping from the bell housing inspection cover of a rear-wheel-drive vehicle. The most likely source is:

  1. the transmission pan gasket
  2. a cooler line fitting at the radiator
  3. the front pump seal or converter hub Correct answer.
  4. the extension housing output seal

Explanation

Fluid inside the bell housing can only come from the pump area, the converter, or the input shaft, which makes the pump seal and the converter hub the prime suspects. The hub should be checked for a groove or burr before a new seal is installed.

Question 31General Transmission and Transaxle Diagnosis

A shift solenoid is being checked with a digital ohmmeter. The reading should be compared with:

  1. the system battery voltage
  2. the throttle position sensor voltage
  3. the published line pressure specification
  4. the manufacturer's specification for that solenoid Correct answer.

Explanation

Coil resistance varies widely between solenoid designs, so only the value published for that part number is meaningful. A reading far above or below specification indicates an open or shorted coil.

Question 32General Transmission and Transaxle Diagnosis

A whine is heard in PARK and NEUTRAL and its pitch rises with engine speed. The most likely source is:

  1. a failing differential bearing
  2. a worn output shaft bearing
  3. a loose converter-to-flexplate bolt
  4. the transmission fluid pump Correct answer.

Explanation

In PARK and NEUTRAL the output shaft and gear train are stationary, so noise that tracks engine speed must come from something the engine drives, such as the pump or converter. Pump whine can result from wear, aeration, or a restricted filter.

Question 33General Transmission and Transaxle Diagnosis

A transmission that has been overfilled by one quart is most likely to:

  1. aerate the fluid and force it out the vent Correct answer.
  2. shift harshly only when the fluid is cold
  3. delay reverse engagement only when cold
  4. whine only when operating in fourth gear

Explanation

An excessive level puts the rotating assembly into the fluid, churning it into foam. Aerated fluid compresses, so apply pressures fall and clutches slip, while the extra volume is pushed out of the breather.

Question 34General Transmission and Transaxle Diagnosis

Scan data shows 50 mph from the vehicle speed sensor while the transmission output speed sensor reads 0 rpm. The most likely cause is:

  1. a forward clutch that is worn
  2. line pressure that is below specification
  3. an open output speed sensor circuit Correct answer.
  4. a converter clutch solenoid stuck open

Explanation

The output speed sensor should report a signal that rises with vehicle speed, so a constant zero while the vehicle is moving points to the sensor, its connector, or its wiring. A clutch or pressure fault would change shift quality but would not zero the signal.

Question 35General Transmission and Transaxle Diagnosis

A vehicle's engine stalls as the vehicle comes to a stop with the brakes applied, then restarts normally in PARK. The most likely cause is:

  1. the converter clutch staying applied Correct answer.
  2. a leaking forward clutch piston
  3. a failed stator one-way clutch
  4. a restricted cooler line

Explanation

If the converter clutch does not release as the vehicle slows, the engine stays locked to the drivetrain and is dragged down to a stall. The release circuit, the solenoid, and the brake switch input to the module should all be checked.

Question 36General Transmission and Transaxle Diagnosis

The transmission control fuse blows as soon as the ignition is switched on. The technician should first:

  1. replace the TCM and retest the vehicle
  2. check the solenoid feed for a short Correct answer.
  3. replace all of the shift solenoids
  4. remove the pan and inspect the valve body

Explanation

A fuse that blows immediately at power-up means a protected circuit is shorted to ground, so the feed wiring and connectors must be checked before any part is replaced. Disconnecting loads one at a time and watching for the fuse to hold narrows the location of the short.

Question 37General Transmission and Transaxle Diagnosis

A transmission flares during the 2-3 upshift only. This most likely indicates:

  1. a worn pump reducing flow in all gears
  2. a leaking 3rd gear apply circuit Correct answer.
  3. low line pressure affecting every range
  4. a slipping converter clutch during lockup

Explanation

A flare means the offgoing element releases before the oncoming element applies with enough capacity. When only one shift is affected, the fault lies in that gear's apply clutch, its piston seals, or the hydraulic circuit feeding it.

Question 38General Transmission and Transaxle Diagnosis

A vehicle with a weak battery and low charging voltage shifts harshly and stores several solenoid codes. The most likely explanation is:

  1. system voltage that is too low Correct answer.
  2. a governor assembly that has failed
  3. a valve body that is worn
  4. a filter that is restricted

Explanation

Electronic transmissions are sensitive to supply voltage; below the operating threshold the module may default to a fixed-pressure mode and set solenoid codes. Charging system voltage should be verified before any internal transmission repair is attempted.

Question 39General Transmission and Transaxle Diagnosis

After an overhaul, transmission shifts are firm for the first few drive cycles and then gradually smooth out. The technician should conclude that:

  1. a shift solenoid is sticking
  2. the fluid level is too low
  3. the TCM is applying adaptive learning Correct answer.
  4. the clutch packs are wearing in

Explanation

Most electronic transmissions adapt apply pressure using speed sensor feedback, trimming pressure until shift time meets target. Firm shifts that smooth out over several drive cycles are the expected result of that adaptive process.

Question 40General Transmission and Transaxle Diagnosis

On a fully electronic transmission, overall line pressure is controlled by the:

  1. 1-2 shift solenoid
  2. 3-2 downshift solenoid
  3. converter clutch apply solenoid
  4. pressure control (EPC) solenoid Correct answer.

Explanation

The electronic pressure control solenoid regulates line pressure by trimming pressure in the regulator circuit in response to current commands from the module. Shift solenoids instead direct fluid to the individual shift valves to select a gear.

Question 41General Transmission and Transaxle Diagnosis

A front-wheel-drive vehicle has a humming noise from the transaxle that gets louder in a turn and changes when the vehicle is steered left and right. The most likely cause is:

  1. a worn fluid pump
  2. a failing converter
  3. a worn differential side bearing Correct answer.
  4. a worn planetary gear carrier

Explanation

Noise that changes with steering direction is loaded and unloaded as the differential side gears and bearings change speed relative to one another. That pattern points to the final drive or differential bearings rather than to the transmission gear train.

Question 42General Transmission and Transaxle Diagnosis

A transmission works normally in all forward gears but has no reverse. The most likely cause is:

  1. a 2-3 shift solenoid stuck on
  2. a failed low/reverse clutch or band Correct answer.
  3. a slipping forward clutch
  4. a slipping converter clutch

Explanation

Reverse uses a dedicated apply element, usually a low/reverse clutch or a rear band, that is not applied in the forward ranges. When every forward gear is fine, the fault is isolated to that element or the hydraulic circuit that feeds it.

Question 43General Transmission and Transaxle Diagnosis

A scan tool displays transmission fluid temperature as -40 degrees Fahrenheit on a fully warmed engine. The most likely cause is:

  1. a failed converter clutch solenoid
  2. a restricted transmission cooler
  3. a thermostat stuck open
  4. an open fluid temperature sensor circuit Correct answer.

Explanation

A reading pinned at the bottom of the scale usually means the sensor circuit is open, because an open thermistor reads as maximum resistance, which the module interprets as extreme cold. The sensor and its wiring should be checked against a resistance chart.

Question 44General Transmission and Transaxle Diagnosis

A transmission slips only after the fluid reaches full operating temperature. Which is the most likely cause?

  1. a shift solenoid that sticks when hot
  2. internal leaks that open as fluid thins Correct answer.
  3. a throttle valve cable adjusted too tight
  4. a breather that is restricted by dirt

Explanation

Hot fluid has lower viscosity, so worn seals, bushings, and valve body clearances leak more and apply pressure falls. Slip that appears only at operating temperature is a classic sign of internal leakage rather than an electrical fault.

Question 45General Transmission and Transaxle Diagnosis

A customer complains of a harsh 1-2 upshift at light throttle only. The most likely cause is:

  1. a worn forward clutch
  2. a failed converter clutch solenoid
  3. a broken 1-2 accumulator spring Correct answer.
  4. a low fluid level

Explanation

The accumulator cushions an apply by absorbing part of the apply pressure, and its effect is most noticeable at light throttle. A broken spring or a stuck accumulator piston removes that cushioning and produces a harsh shift.

Question 46General Transmission and Transaxle Diagnosis

Engagement into drive and reverse is harsh and line pressure is above specification in every range. The throttle position signal and the throttle valve cable are correct. The most likely cause is:

  1. a restricted cooler line
  2. a failed converter clutch solenoid
  3. a worn forward clutch pack
  4. a pressure regulator stuck at maximum Correct answer.

Explanation

When line pressure is high in every range while the throttle signal is correct, the regulator circuit is not responding to command. A stuck regulator valve, a disconnected solenoid, or a broken regulator spring holds pressure at maximum and makes every engagement harsh.

Question 47General Transmission and Transaxle Diagnosis

A vehicle sets a converter clutch slip code. Line pressure is within specification, the TCC solenoid clicks when commanded, the fluid is clean, and all gear shifts are normal. The most likely cause is:

  1. an open output shaft speed sensor circuit
  2. a restricted transmission filter
  3. a worn forward clutch pack
  4. a leaking converter clutch apply circuit Correct answer.

Explanation

With correct line pressure, normal shifts, and a solenoid that responds, the remaining path for lockup slip is the apply circuit itself or the clutch lining inside the converter. Either one lets the clutch slip under commanded load while everything else behaves normally.

Question 48General Transmission and Transaxle Diagnosis

Two shift solenoids share a common ground wire inside the transmission, and both stop working at the same moment. The most likely cause is:

  1. both solenoid coils failed at the same time
  2. a restricted transmission filter
  3. an open in the shared ground wire Correct answer.
  4. the TCM lost its ignition feed

Explanation

A shared circuit that fails takes every load connected to it, so two solenoids dropping out together points to the common ground path rather than to the individual coils. A voltage drop test from the solenoid ground pin to battery negative confirms the open.

Question 49General Transmission and Transaxle Diagnosis

A vehicle intermittently fails to upshift after about 30 minutes of driving and returns to normal after it cools. Which approach is most likely to identify the cause?

  1. perform a stall test with the transmission cold
  2. adjust the throttle valve cable on a cold engine
  3. monitor solenoid resistance while the fault is present Correct answer.
  4. replace the TCM and retest the vehicle

Explanation

A fault that appears only at operating temperature usually comes from a component whose resistance or clearance changes with heat, so it has to be tested while the symptom exists. Watching scan data and coil resistance during the event captures the failing circuit in the act.

Question 50General Transmission and Transaxle Diagnosis

Line pressure is within specification at idle in drive but falls well below specification when engine speed is raised in gear. The most likely cause is:

  1. a slipping converter clutch
  2. a restricted filter or a weak pump Correct answer.
  3. a shift solenoid stuck open
  4. fluid that is too cold to circulate

Explanation

Pressure that drops as pump speed rises means the pump cannot draw enough fluid, which usually points to a restricted filter or pick-up or to a worn pump. Comparing pressure at the pump outlet with a known-good filter isolates a suction restriction from a pump fault.