ASE Certification Guide

ASE G1 · practice questions

ASE G1 practice test: 54 questions

54 questions spread over the seven G1 content areas in about the proportion of the scored test, so suspension and steering and brakes get the most. Each answer opens a note on every option, so you see why the near-misses are wrong too. The area chips let you drill one area at a time.

  • 54practice questions here
  • 65questions on the test
  • 90 minto answer them
  • Not publishedpassing score

Questions

0 of 54 answered · 0 correct
Question 1 of 54 · Automatic Transmission/Transaxle · 7%Not answered

A technician is preparing to check the fluid level on a sealed automatic transmission equipped with a standpipe overflow plug. Which specific operating condition must be met regarding the engine state before removing the fluid level check plug?

Explanation

Incorrect: A cold check is wrong because the procedure ties the check to a specified fluid temperature, and ATF expands as it warms.

Correct: On a standpipe unit the level is checked with the engine idling at the specified fluid temperature, so the pump keeps the circuits full while the excess drains from the plug.

Incorrect: The selector is cycled through the gears and then left in Park for the check; it is not held in Reverse.

Incorrect: The vehicle must sit level on the hoist; with the rear wheels raised the unit tilts the fluid and gives a false level.

Incorrect: With the engine off, fluid drains back from the converter and circuits into the pan, and too much runs out of the plug.

Question 2 of 54 · Automatic Transmission/Transaxle · 7%Not answered

A technician is checking the automatic transmission fluid (ATF) level on a vehicle with a dipstick. The engine is idling at operating temperature in Park. What is the correct procedure to obtain an accurate reading?

Explanation

Incorrect: This procedure calls for a running engine; shutting it off lets fluid drain back and the level reads high.

Incorrect: The first pull carries splash from the filler tube, so the line it shows is unreliable.

Incorrect: A partly inserted dipstick does not reach its calibrated depth, so the reading means nothing.

Incorrect: Adding fluid before reading the level risks overfilling, which aerates the fluid.

Correct: The first pull is smeared by fluid splashing in the tube; wiping the stick and seating it fully gives a clean, accurate line.

Question 3 of 54 · Automatic Transmission/Transaxle · 7%Not answered

A service manual states that the transmission fluid level check must be performed when the fluid temperature is between 80°C and 90°C. The technician's scan tool indicates a fluid temperature of 185°F. What is the equivalent Celsius temperature and status?

Explanation

Incorrect: 88°C would be about 190°F; the status happens to be right, but the conversion is not.

Incorrect: 78°C comes from the rough 'subtract 30 and halve' shortcut; the exact conversion gives 85°C.

Correct: (185 − 32) × 5/9 = 85°C, inside the 80–90°C window, so the check can proceed.

Incorrect: 103 comes from 185 × 5/9 without first subtracting 32.

Incorrect: 153 is 185 − 32 without the × 5/9 step, so it is not a Celsius value.

Question 4 of 54 · Automatic Transmission/Transaxle · 7%Not answered

During an inspection, the transmission fluid on the dipstick appears pink and foamy. The fluid level reads significantly above the "HOT FULL" mark. What is the most likely cause of this condition?

Explanation

Incorrect: A restricted filter starves the pump and causes delayed or slipping shifts; it does not raise the level above full.

Incorrect: Overheating darkens fluid and gives it a burnt smell; pink, foamy fluid above full points to overfill.

Correct: In an overfilled unit the level sits above HOT FULL and rotating parts whip the fluid into foam; draining to the correct level is the fix.

Incorrect: The wrong fluid can cause shift problems, but it does not push the level far above the full mark.

Incorrect: A low level can aerate fluid too, but this dipstick reads well above HOT FULL.

Question 5 of 54 · Brakes · 20%Not answered

A technician measures 0.006" (0.15 mm) of lateral runout on a brake rotor. The maximum specification is 0.002" (0.05 mm). The rotor surface condition is good and thickness is well above minimum. What should the technician do first?

Explanation

Incorrect: Nothing suggests the dial indicator is faulty; 0.006 in. is a believable stack-up reading.

Incorrect: Machining removes material the rotor does not need to lose; it comes only if indexing and a hub check leave runout out of spec.

Incorrect: The hub is replaced only after its own runout measures out of spec; nothing here condemns it yet.

Incorrect: The rotor is in good condition and well above minimum thickness, so replacing it before indexing wastes a good part.

Correct: Runout on a rotor in good condition often comes from how it stacks on the hub; indexing it to a new stud position and re-measuring is the first, no-cost step.

Question 6 of 54 · Brakes · 20%Not answered

An ABS warning light flashes intermittently at highway speeds. A scan tool shows a code for erratic signal from the right front wheel speed sensor. Visual inspection reveals a hairline crack in the tone ring. What is the correct repair?

Explanation

Incorrect: Cleaning the sensor mount helps a loose or dirty sensor, but the fault found here is a crack in the ring.

Incorrect: The ABS module is correctly flagging a bad signal; replacing it does not fix the cracked ring.

Incorrect: The wheel speed sensor is reading a damaged ring; a new sensor would read the same crack.

Incorrect: Most wheel speed sensors have a fixed air gap, and no gap setting can hide a cracked tone ring.

Correct: A cracked tone ring gives an erratic signal each time the crack passes the sensor; replacing the ring (or the hub or axle it is part of) is the fix.

Question 7 of 54 · Brakes · 20%Not answered

A technician needs to measure a brake rotor to check for parallelism (thickness variation). Which method describes the correct way to take measurements using a micrometer?

Explanation

Correct: Thickness variation is found by measuring with a micrometer at several evenly spaced points (eight or more) around the rotor, the same distance in from the edge, and comparing them.

Incorrect: The hub mounting flange is not the friction surface; thickness there says nothing about the braking face.

Incorrect: The thinnest point checks discard thickness; parallelism needs a set of readings to compare, not one minimum.

Incorrect: Wheel studs are not on the rotor face; measuring across them does not measure rotor thickness.

Incorrect: A single reading cannot show variation, and the very outer edge sits outside the pad path.

Question 8 of 54 · Brakes · 20%Not answered

An ABS warning light is on with a DTC indicating "Right Front Wheel Speed Sensor Circuit Open." A technician proposes replacing the ABS control module. What should be performed first?

Explanation

Correct: A circuit-open code means the module sees no complete sensor circuit; checking the sensor, connector and harness comes before any parts.

Incorrect: Steering angle sensor calibration does not address an open circuit at a wheel speed sensor.

Incorrect: Replacing the wheel speed sensor without testing skips the harness and connector, where an open circuit is often found.

Incorrect: Clearing the trouble code erases the evidence; with an open circuit the code returns on the next drive.

Incorrect: An electrical open in a sensor circuit has nothing to do with air in the hydraulic system.

Question 9 of 54 · Brakes · 20%Not answered

A customer reports a high-pitched squeal when braking lightly. Inspection shows the pads have 70% life remaining and the rotors are in good condition. The pad clips and shims look old, discolored and loose. What is the most likely cause?

Explanation

Correct: Old, heat-fatigued clips and shims stop holding and damping the pads, so the pads vibrate and squeal under light braking.

Incorrect: Seized caliper pins cause drag and uneven pad wear, not a squeal from loose pads.

Incorrect: Air in the brake lines makes the pedal spongy; it does not make noise.

Incorrect: A low brake fluid level lights the brake warning lamp; it has nothing to do with pad noise.

Incorrect: The rotors are in good condition, and runout causes pulsation rather than a squeal.

Question 10 of 54 · Brakes · 20%Not answered

A floating caliper is seized, and the rubber dust boots are found to be swollen and soft. Which lubricant was likely used during the previous service?

Explanation

Incorrect: High-temperature silicone brake lubricant is made to be safe on caliper rubber; it does not swell the boots.

Incorrect: Dry graphite powder does not swell rubber; it simply wears away and leaves the pins dry.

Incorrect: Poly-glycol assembly fluid shares the base of DOT 3/4 brake fluid, so it is safe for brake rubber.

Correct: Petroleum products attack the EPDM rubber of caliper boots and seals, making them swell and soften.

Incorrect: Synthetic ceramic caliper grease is a brake-specific product that is compatible with the boots.

Question 11 of 54 · Brakes · 20%Not answered

A technician is measuring lateral runout on a floating rotor. To ensure a valid reading, which step must be performed before using the dial indicator?

Explanation

Correct: A floating rotor is held to the hub only by the wheel; lug nuts (with spacers if needed) torqued to spec clamp it flat so the dial indicator reads true runout.

Incorrect: Loosening the wheel bearing nut adds play that shows up as false runout.

Incorrect: Pushing the caliper pistons back is part of pad service; it does not affect how the rotor sits on the hub.

Incorrect: Sanding the rotor face does not change runout, which depends on how the rotor sits and how flat it is.

Incorrect: Applying the parking brake keeps the rotor from turning, and the rotor has to rotate for the reading.

Question 12 of 54 · Brakes · 20%Not answered

A customer states that their vehicle emits a loud metal-on-metal grinding noise coming from the front right wheel area while driving. A visual inspection confirms that the inner and outer brake pads exceed minimum thickness specifications and the caliper is functioning correctly. What is the most likely cause of this noise?

Explanation

Incorrect: The caliper was checked and works correctly, and a seized slide pin causes drag and uneven wear, not grinding.

Incorrect: Both pads measured above minimum, so worn-out friction material is ruled out.

Incorrect: A glazed rotor surface reduces friction and squeals; it does not grind metal on metal.

Incorrect: Rotor runout causes pedal pulsation, not a constant grinding noise.

Correct: A stone caught between the rotor and its dust shield scrapes metal on metal while driving, even with good pads and a working caliper.

Question 13 of 54 · Electrical · 15%Not answered
Measurement TypeReading
Surface Charge12.9 V
Rest Voltage12.4 V
Load Voltage9.8 V

A technician performs an open-circuit voltage test on a standard flooded lead-acid battery. The vehicle has been sitting overnight. Based on the readings in the table, what is the approximate state of charge?

Explanation

Incorrect: 0% would come from reading the 9.8 V load voltage, which is not a state-of-charge measurement.

Incorrect: 100% needs about 12.6–12.7 V at rest; the 12.9 V surface charge reading overstates the charge.

Incorrect: 50% is about 12.2 V at rest, and 12.4 V is higher than that.

Correct: State of charge is read from rest voltage once surface charge is gone; 12.4 V corresponds to about 75%.

Incorrect: 25% is about 12.0 V at rest, well below the 12.4 V measured.

Question 14 of 54 · Electrical · 15%Not answered

A customer returns with a headlamp bulb failure only two weeks after replacement. The technician removes the bulb and notes a blistered white spot on the glass envelope. What is the most likely cause?

Explanation

Correct: Skin oil left on a halogen capsule creates a hot spot that blisters the quartz glass and makes the bulb fail early; new bulbs are handled by the base or with gloves.

Incorrect: A loose headlamp assembly breaks filaments through vibration; it does not blister the glass.

Incorrect: High charging voltage shortens the life of every bulb by overheating the filament, without a single blistered spot.

Incorrect: Moisture in the housing fogs the lens and corrodes sockets, but it does not blister one spot on the glass.

Incorrect: A short in the wiring blows a fuse or kills the lamp; it does not mark the glass.

Question 15 of 54 · Electrical · 15%Not answered

While diagnosing a no-start condition, a technician pulls on a fusible link in the starter circuit and notices the insulation feels soft and stretches significantly. What does this indicate?

Explanation

Correct: A good fusible link feels firm; when it stretches like soft rubber, the conductor inside has melted open even though the insulation is unbroken.

Incorrect: Oil-soaked insulation swells and softens, but a link that stretches when pulled points to a melted conductor.

Incorrect: A loose crimp shows up as heat or high resistance at the terminal, not as a stretchy link.

Incorrect: A fusible link is deliberately smaller in gauge than the wire it protects; that is its design, not a fault.

Incorrect: The insulation looks whole, but the stretch shows the conductor inside is gone, so the link is not intact.

Question 16 of 54 · Electrical · 15%Not answered

During an inspection, a technician notes that the battery hold-down hardware is missing, allowing the battery to move. What is the primary long-term risk of this condition?

Explanation

Correct: An unsecured battery is shaken by road vibration, which loosens plate material and breaks internal connections, shortening its life.

Incorrect: Terminal post oxidation comes from acid vapor and moisture, not from a loose battery.

Incorrect: Reduced electrolyte levels come from heat and overcharging, not from a missing hold-down.

Incorrect: Case swelling from heat is caused by overcharging or high temperature, not by movement.

Incorrect: Faster sulfation comes from a battery sitting discharged, not from it moving in the tray.

Question 17 of 54 · Electrical · 15%Not answered

A vehicle battery consistently dies overnight. A technician fully charges the battery, disconnects the negative cable, and lets it sit for 12 hours. The open-circuit voltage remains at 12.6 V. When the battery is reconnected to the vehicle, the voltage drops to 10.5 V by the next morning. What is the most likely cause?

Explanation

Incorrect: Dirt across the case can leak a small current, but the battery held its charge while sitting by itself.

Incorrect: An internal battery short would drain it even while disconnected, and it held 12.6 V.

Correct: The battery holds 12.6 V for 12 hours on its own but drains overnight when connected, so something in the vehicle is drawing current with the key off.

Incorrect: Sulfated plates lose capacity, but they would not make the battery drop to 10.5 V only when it is connected.

Incorrect: Stratification affects capacity and readings; it does not drain the battery only when connected to the vehicle.

Question 18 of 54 · Electrical · 15%Not answered

While performing a wiggle test to find a loose connector that is causing intermittent engine stalling, which multimeter function should the technician use to capture brief voltage drops by recording the lowest and highest readings over time?

Explanation

Incorrect: Relative mode zeroes the display to a reference value; it does not record dips.

Incorrect: Data Hold freezes one reading on the display; it does not track the lowest value over time.

Correct: Min/Max mode records the lowest and highest readings while the harness is wiggled, catching a brief voltage drop the display would miss.

Incorrect: Peak Hold keeps the single highest instantaneous peak; it does not log the lowest and highest readings the way Min/Max does.

Incorrect: Auto Range only selects the measuring range; it records nothing.

Question 19 of 54 · Electrical · 15%Not answered

A vehicle's fuel pump will not run. With the pump connector unplugged, a technician measures 0.2 ohm (shows continuity) on the power lead. However, when the pump is connected and the circuit is powered, the voltage at the pump connector drops to 4.0 volts under load. What is the most likely reason for these apparently conflicting test results?

Explanation

Incorrect: A pump relay stuck closed keeps power on the pump all the time; it does not lower voltage under load.

Incorrect: A fuse rated too high removes protection, but it does not cause a voltage drop on a sound wire.

Incorrect: A power lead shorted to ground would blow the fuse rather than leave 4.0 V at the pump.

Correct: A wire with only a few strands left, or corrosion inside, can read 0.2 ohm with almost no current yet drop most of the voltage once the pump draws current; a loaded voltage drop test finds it.

Incorrect: An out-of-calibration multimeter would not explain why the voltage collapses only when the pump is loaded.

Question 20 of 54 · Electrical · 15%Not answered

A technician measures 0.5 volts between the negative battery post and the negative terminal clamp while the engine is cranking. What is the correct repair for this condition?

Explanation

Incorrect: The drop was measured at the clamp contact, not along the cable; the ground cable is replaced only if it is damaged too.

Incorrect: A parasitic draw test looks for key-off drains; it does not address a resistive connection while cranking.

Incorrect: The starter motor is not part of the post-to-clamp measurement.

Correct: The 0.5 V drop is across the post-to-clamp contact itself, so cleaning the post and clamp and tightening the clamp fixes the high resistance.

Incorrect: The drop is outside the battery, at the connection, so the battery is not condemned.

Question 21 of 54 · Electrical · 15%Not answered

A starter motor clicks but does not turn. Battery voltage stays at 12.2 V during the attempt, the total circuit voltage drop is 0.3 V, and the starter current draw is only 50 amps. What is the most likely cause?

Explanation

Incorrect: A seized engine bearing makes the starter draw very high current, not 50 A.

Incorrect: An open neutral switch stops the solenoid from clicking at all, and here it clicks.

Correct: Good battery voltage, a low cable drop and very low current mean power reaches the starter but the motor does not draw its load: an open in its brushes, windings or solenoid contacts.

Incorrect: Battery voltage holds at 12.2 V during the attempt, so a discharged battery is ruled out.

Incorrect: A total drop of 0.3 V shows the cables are not restricting current.

Question 22 of 54 · Engine Systems · 16%Not answered

A technician is replacing a radiator hose on a vehicle with a plastic radiator neck. The original clamp is missing. Which type of clamp is recommended to prevent damage to the plastic component while ensuring a proper seal?

Explanation

Incorrect: A rolled edge protects the hose cover, but a worm-gear clamp still applies fixed, screw-driven force that can crack plastic.

Incorrect: A T-bolt clamp gives very high clamping force for high-pressure hoses and can crack a plastic neck.

Incorrect: A worm-drive clamp is easy to overtighten on a plastic neck, and it does not follow the hose as it shrinks when cold.

Incorrect: A double-wire clamp concentrates force on two thin lines and can cut the hose or stress the plastic neck.

Correct: A constant-tension spring clamp keeps even pressure as the hose and plastic neck expand and shrink, without the overtightening that cracks plastic.

Question 23 of 54 · Engine Systems · 16%Not answered

While inspecting radiator hoses, a technician finds that the hose rubber feels soft and spongy near the clamp, while the middle section is firm. What does this condition indicate?

Explanation

Incorrect: Abrasion wears through the outer cover where the hose rubs; it does not make the rubber spongy.

Incorrect: Heat cycling hardens a hose along its whole length rather than softening one end.

Correct: Electrochemical degradation attacks the hose from the inside near the metal fittings and clamps, leaving it soft and spongy there while the middle stays firm.

Incorrect: Ozone damage from the environment makes fine surface cracks on the outside, not soft rubber near the clamp.

Incorrect: Excessive system pressure would balloon or burst a weak spot; it does not soften only the hose ends.

Question 24 of 54 · Engine Systems · 16%Not answered

During a cooling system pressure test, the technician confirms the tester adapter is sealed on the filler neck and pumps the tester to the specified pressure, but the gauge needle drops rapidly to zero in less than 5 seconds. What is the most likely cause?

Explanation

Incorrect: A porous block casting weeps slowly and would show as a slow pressure loss.

Incorrect: Head gasket seepage lets pressure fall slowly over minutes, not to zero in seconds.

Incorrect: A hairline head crack leaks into a cylinder or the oil slowly; it does not drop pressure to zero almost at once.

Incorrect: A pinhole heater core leak bleeds pressure off gradually; it cannot dump the pressure in five seconds.

Correct: Pressure that falls to zero within seconds means coolant is escaping fast, which points to a large external leak such as a split hose or an open drain.

Question 25 of 54 · Engine Systems · 16%Not answered

Technician A removes the pressurized coolant reservoir cap on a hot engine and tops off to the MAX line. Technician B says that the coolant level should be checked against the COLD FULL mark after the engine has cooled to ambient temperature. Who is correct?

Explanation

Incorrect: Technician A is wrong: opening a pressurized reservoir on a hot engine can spray scalding coolant, and a hot level does not match the COLD FULL mark.

Correct: Technician B is right: the level is checked on a cooled engine against the COLD FULL mark, when the cap can be removed safely.

Incorrect: Technician A's hot, cap-off top-off is unsafe and reads the wrong mark, so both cannot be correct.

Incorrect: Technician B describes the correct check, so rejecting both is wrong.

Question 26 of 54 · Engine Systems · 16%Not answered

A vehicle is being serviced for operation in a region where temperatures frequently drop to -30°F (-34°C). Technician A recommends using a 60% antifreeze / 40% water mixture. Technician B recommends using a 70% water / 30% antifreeze mixture. Which technician is correct?

Explanation

Correct: Technician A is right: a 60% antifreeze mix protects to about −60°F, well below −30°F, and stays within the range manufacturers allow.

Incorrect: Technician B is wrong: 30% antifreeze protects only to about +5°F, far short of −30°F.

Incorrect: A 30% mix would freeze well above −30°F, so both cannot be correct.

Incorrect: Technician A's 60/40 mix gives the needed protection, so rejecting both is wrong.

Question 27 of 54 · Engine Systems · 16%Not answered

During a cooling system pressure test, the gauge drops 5 psi in 2 minutes. There are no puddles on the floor. Technician A says the cylinder head gasket is definitely failed. Technician B says to check the pressure tester connections and hose clamps first. Who is correct?

Explanation

Incorrect: Technician A is wrong to call the head gasket 'definitely' failed: with no visible leak, the tester connections and clamps are checked first.

Correct: Technician B is right: a loose adapter or hose clamp is a common, easy cause of pressure loss and is ruled out before internal leaks are suspected.

Incorrect: Technician A jumps to a conclusion the test does not support, so both cannot be right.

Incorrect: Technician B's first step is correct, so rejecting both is wrong.

Question 28 of 54 · Engine Systems · 16%Not answered

While inspecting a vehicle with a low coolant level, a technician observes white, crusty residue along the crimp seal where the plastic tank meets the aluminum core. What is the correct repair?

Explanation

Incorrect: Bending the tabs with pliers seldom reseals the gasket and can crack the plastic tank.

Incorrect: Epoxy does not bond reliably to the plastic tank under heat and pressure, so the seam leaks again.

Incorrect: A lower pressure cap lowers the boiling point and invites overheating without fixing the leak.

Correct: White crust at the tank-to-core crimp is dried coolant from a failed tank gasket; plastic-tank radiators are replaced rather than resealed in service.

Incorrect: Stop-leak can clog the radiator and heater core and is not a proper repair for a seam leak.

Question 29 of 54 · Engine Systems · 16%Not answered

During a warm-up cycle, a technician observes coolant flowing into the reservoir as the engine reaches operating temperature. There are no bubbles present in the flow. What does this condition indicate about the cooling system?

Explanation

Correct: As coolant heats it expands and the pressure cap releases the excess to the reservoir; a steady, bubble-free flow is normal.

Incorrect: The cap's vacuum valve works on cool-down, drawing coolant back; it does not explain flow during warm-up.

Incorrect: Air trapped in the heater core circuit would show as bubbles and gurgling, which are absent here.

Incorrect: A restricted radiator core causes overheating, not a calm, bubble-free flow into the reservoir.

Incorrect: A leaking head gasket pushes combustion gas into the coolant, which shows as bubbles in the flow.

Question 30 of 54 · Engine Systems · 16%Not answered

A technician prepares to measure fuel pressure on a port fuel injection system. The engine has two test ports with Schrader valves: one on the fuel rail and one near the brake booster with a green cap. Which action is correct?

Explanation

Incorrect: A green cap marks the EVAP service port, which holds vapor at low pressure, not fuel pressure.

Incorrect: The EVAP port has nothing to do with fuel pressure, so averaging it with the rail reading is meaningless.

Incorrect: Removing the green port's Schrader core opens the EVAP system and still gives no fuel pressure reading.

Correct: The fuel rail Schrader port is the fuel pressure test point; the green-capped port near the booster belongs to the EVAP system.

Incorrect: Adapting the gauge to the EVAP port measures vapor system pressure, not fuel pressure.

Question 31 of 54 · Heating, Ventilation, and Air Conditioning · 7%Not answered

An A/C system is blowing warm air. The technician finds both the low-side and high-side pressures are significantly below the manufacturer's specifications. What is the most likely cause?

Explanation

Incorrect: Blocked condenser airflow raises high-side pressure, the opposite of what was measured.

Incorrect: An overcharge drives both pressures above specification, not below.

Correct: Both sides low with warm air is the classic low-charge pattern: there is not enough refrigerant to build pressure on either side.

Incorrect: An expansion valve stuck open floods the evaporator, raising low-side pressure rather than lowering it.

Incorrect: A failed cooling fan raises high-side pressure, especially at idle.

Question 32 of 54 · Heating, Ventilation, and Air Conditioning · 7%Not answered

A technician identifies that the R-134a refrigerant in a customer's vehicle is contaminated with a sealant and cannot be reused. What is the required method for disposal?

Explanation

Incorrect: Filtering does not reliably remove sealant, and contaminated refrigerant is not reused.

Incorrect: Recycling with the shop machine would spread sealant through the machine and into other vehicles.

Incorrect: Venting refrigerant into the shop exhaust is illegal under the Clean Air Act, even when it is contaminated.

Correct: Refrigerant contaminated with sealant cannot be recycled on site; it is recovered with dedicated equipment into a separate container and sent out for reclamation or destruction.

Incorrect: Refrigerant is not mixed with waste oil; it is a regulated gas that must be recovered.

Question 33 of 54 · Heating, Ventilation, and Air Conditioning · 7%Not answered

A system has a factory specified charge of 600 grams. During recovery, the technician removes 550 grams of refrigerant. The manufacturer's charge tolerance for this system is ±10%. What is the correct assessment?

Explanation

Incorrect: A loss of about 8% stays within tolerance, so it does not prove a leak requiring immediate repair.

Incorrect: 550 g is less than the 600 g specification, so the system was not overcharged.

Incorrect: The recovered charge is within tolerance, so nothing points to a leaking compressor shaft seal.

Correct: 550 g is about 92% of the 600 g specification, inside the 540–660 g window that ±10% allows, so the charge is within tolerance.

Incorrect: A recovered amount within tolerance gives no reason to doubt the recovery machine.

Question 34 of 54 · Manual Drive Train and Axles · 11%Not answered

Technician A says that only factory-style ear clamps or crimp bands should be used to secure CV boots. Technician B says that heavy-duty nylon zip-ties are an acceptable permanent replacement for CV boot clamps. Who is correct?

Explanation

Correct: Technician A is right: CV boots are secured with the ear clamps or crimp bands made for them, which stay tight through heat and flexing.

Incorrect: Technician B is wrong: nylon zip-ties loosen and break from heat and joint movement, letting grease out and dirt in.

Incorrect: Zip-ties are not an acceptable permanent clamp, so both cannot be correct.

Incorrect: Technician A states the correct practice, so rejecting both is wrong.

Question 35 of 54 · Manual Drive Train and Axles · 11%Not answered

A technician is diagnosing a driveline vibration that persists after the driveshaft was balanced. Which component should be inspected next?

Explanation

Incorrect: Front brake pads affect braking only, not a vibration while driving.

Incorrect: Wheel speed sensors report speed to the ABS; they cannot cause a driveline vibration.

Incorrect: Loose steering linkage causes wander and shimmy, not a vibration that tracks driveline speed.

Incorrect: Worn sway bar links clunk over bumps; they do not cause a speed-related driveline vibration.

Correct: Worn or collapsed transmission mounts change driveline working angles, so a balanced shaft can still vibrate.

Question 36 of 54 · Manual Drive Train and Axles · 11%Not answered

A vehicle exhibits a vibration at highway speed. A vibration analyzer detects the dominant frequency at 48 Hz. At this speed, the wheels are rotating at 14 Hz, and the axle ratio is 3.42:1. Which component is the most likely source of the vibration?

Explanation

Incorrect: The torque converter clutch turns at engine speed, which does not match 14 Hz × 3.42.

Correct: The driveshaft turns at wheel speed times the axle ratio: 14 Hz × 3.42 ≈ 48 Hz, which matches the vibration.

Incorrect: A rear axle bearing turns at wheel speed and makes noise rather than a 48 Hz vibration.

Incorrect: An engine mount passes on vibration tied to engine RPM, not a frequency locked to driveshaft speed.

Incorrect: A tire vibration would occur at wheel speed, 14 Hz, not 48 Hz.

Question 37 of 54 · Manual Drive Train and Axles · 11%Not answered

A vibration analyzer attached to a vehicle indicates a significant second-order vibration (two disturbances per revolution) relative to the driveshaft speed. Which driveline condition is the most consistent with this specific analyzer reading?

Explanation

Incorrect: An engine cylinder misfire follows engine firing frequency, not driveshaft speed.

Incorrect: A tire bead seating issue causes vibration at wheel speed, not at twice driveshaft speed.

Incorrect: A driveshaft balance issue pushes once per revolution, a first-order vibration.

Correct: A U-joint running at an angle speeds up and slows down twice per turn, so unequal or excessive working angles create a second-order driveline vibration.

Incorrect: Tube runout is also a once-per-revolution, first-order disturbance.

Question 38 of 54 · Manual Drive Train and Axles · 11%Not answered

A CV axle boot is found torn with sand and water mixed into the remaining grease. The joint makes a clicking sound when cornering. What is the recommended repair?

Explanation

Incorrect: A split boot is a quick seal for a clean joint; it does nothing for a worn one.

Incorrect: Tape does not seal a CV boot, and fresh grease cannot repair a clicking joint.

Incorrect: The axle nut sets hub clamp load; tightening it does not stop a worn CV joint from clicking.

Correct: Sand and water in the grease and a clicking joint mean the joint is already worn, so replacing the CV joint or axle assembly is the repair.

Incorrect: Re-booting saves a joint only when the tear is caught early; a contaminated, clicking joint is already damaged.

Question 39 of 54 · Manual Drive Train and Axles · 11%Not answered

A technician is performing a visual inspection of a vehicle's CV axle boots for signs of damage or wear. Why is it necessary to manually spread the pleats and flex the joint during this examination?

Explanation

Correct: Cracks hide in the folds of the pleats; spreading them and flexing the joint opens the folds to reveal hidden cracks or tears.

Incorrect: Boot diameter is not a measured service spec; the inspection looks for damage.

Incorrect: UV light finds dye in fluid leaks; it is not how CV boots are checked.

Incorrect: A CV boot is never pressurized with shop air, which can rupture it.

Incorrect: A soapy water spray test finds air leaks in pressurized systems, and a CV boot is not pressurized.

Question 40 of 54 · Manual Drive Train and Axles · 11%Not answered

During a driveshaft inspection for a high-speed vibration complaint, a technician notices a small, clean rectangular area with spot weld marks on an otherwise dirty driveshaft tube. What does this specific visual clue indicate?

Explanation

Incorrect: The weld marks are from factory balancing, but a clean, empty patch on a dirty tube means the weight has come off, which is not normal.

Correct: A clean rectangle with spot weld marks on a dirty tube is where a balance weight used to be; losing it leaves the shaft out of balance at speed.

Incorrect: Heat discoloration shows as a blue or straw tint, not a clean patch with weld marks.

Incorrect: Collision damage shows as dents or bends, not a neat welded rectangle.

Incorrect: A bent driveshaft tube is found with a runout check; it does not leave a clean, welded patch.

Question 41 of 54 · Suspension and Steering · 24%Not answered

A wheel assembly requires 3.5 ounces of weight to balance. The technician notes the assembly has excessive radial runout, though the rim itself is within specifications. What should be done next to correct the condition?

Explanation

Incorrect: The rim is within specification, so replacing the wheel rim does not address the tire's runout.

Incorrect: Grinding tread off the high spot shortens tire life and is not a standard correction; match-mounting is done instead.

Incorrect: Weights on both flanges correct dynamic imbalance, not radial runout.

Incorrect: A counterweight corrects imbalance, not radial runout, which is an out-of-round condition.

Correct: With the rim in spec, the radial runout is in the tire; repositioning (match-mounting) the tire on the wheel lines its high spot up with the rim's low spot.

Question 42 of 54 · Suspension and Steering · 24%Not answered

A vehicle returns with a pulsating brake pedal shortly after a tire rotation service. The technician suspects the lug nuts were tightened unevenly using only an impact wrench. What damage likely occurred?

Explanation

Incorrect: Worn brake pads make noise and lose friction; they do not cause pulsation tied to lug torque.

Incorrect: Seized caliper slide pins cause drag and uneven pad wear, not pulsation right after a rotation.

Incorrect: Stabilizer links have nothing to do with the brake pedal.

Incorrect: Lug torque does not damage wheel bearings in a way that pulses the pedal.

Correct: Uneven impact-wrench torque pulls the rotor hat out of true, creating lateral runout that soon shows as pedal pulsation.

Question 43 of 54 · Suspension and Steering · 24%Not answered

A customer asks for their tires to be inflated to the correct specification. The driver's door placard indicates 32 psi, while the tire sidewall lists a maximum pressure of 44 psi. What cold inflation pressure should be set?

Explanation

Correct: The placard pressure is the vehicle maker's recommended cold inflation for this vehicle and load, so the tires are set to 32 psi cold.

Incorrect: 38 psi averages the placard and the sidewall maximum, which has no basis.

Incorrect: 40 psi overinflates the tire for this vehicle, which reduces grip and wears the tread center.

Incorrect: 35 psi is not the specified pressure; the placard value already covers normal highway driving.

Incorrect: 44 psi is the tire's maximum rating, a limit for the tire, not the pressure for this vehicle.

Question 44 of 54 · Suspension and Steering · 24%Not answered

A vehicle's TPMS light illuminated during a cold snap (10°F / -12°C). After driving to the shop, the light turned off. Measured hot tire pressures currently match the door placard specification. What is the correct course of action?

Explanation

Incorrect: The TPMS control module worked as designed by warning of low cold pressure.

Incorrect: The tire pressure sensors reported correctly: the tires really were low in the cold.

Incorrect: The light followed real pressure changes, so there is no intermittent electrical fault to chase.

Incorrect: A relearn is needed after sensor or position changes, and nothing changed here.

Correct: Pressure drops about 1 psi for every 10°F; hot pressures at placard mean the tires are low when cold, so cold pressures are set to placard spec.

Question 45 of 54 · Suspension and Steering · 24%Not answered

A customer returns to the shop 100 miles after having new aluminum alloy wheels installed, reporting a clicking sound. The technician discovers several loose lug nuts. The initial installation torque was verified correct. Which step was likely omitted from the service procedure?

Explanation

Correct: Alloy wheels can settle against the hub in the first miles, so wheel makers call for a retorque after the first 50–100 miles; skipping it lets the nuts loosen.

Incorrect: Stud thread lubrication changes the torque-to-clamp relationship and can overstretch studs; it is not a missing step.

Incorrect: Thread locking compound is never used on wheel studs; it alters torque and makes removal unsafe.

Incorrect: Hub surfaces are cleaned, not machined, during a wheel install.

Incorrect: Impact wrench tightening causes uneven, incorrect torque; wheels are finished with a torque wrench.

Question 46 of 54 · Suspension and Steering · 24%Not answered

Technician A says that a visual check with the vehicle static is enough to rule out play in the steering linkage. Technician B says that a dry-park check, rocking the steering wheel with the vehicle's weight on the wheels, is a reliable way to find linkage play. Who is correct?

Explanation

Incorrect: Technician A is wrong: worn joints often look fine at rest, and their play appears only when the linkage is loaded.

Correct: Technician B is right: a dry-park check loads the linkage the way driving does, so worn tie rod ends and sockets show movement.

Incorrect: A static look misses loaded play, so both cannot be correct.

Incorrect: Technician B's dry-park method is a standard check, so rejecting both is wrong.

Question 47 of 54 · Suspension and Steering · 24%Not answered

During an under-vehicle inspection, a technician notes the following findings: the lower ball joint has 0.010 in of play (limit 0.050 in), the stabilizer bar bushings have surface cracks, and the cotter pin is missing from the lower ball joint castle nut. Which finding represents the most critical safety concern?

Explanation

Incorrect: Surface cracks on sway bar bushings are a minor wear item, not an immediate safety risk.

Incorrect: A missing cotter pin is not 'in limits'; it is a safety defect.

Incorrect: The ball joint is within limits and the bushings show only surface cracks, so the three findings are not equally urgent.

Correct: Without its cotter pin the castle nut can back off and the ball joint can separate, a loss-of-control hazard, so it is the most critical finding.

Incorrect: 0.010 in. of ball joint play is well inside the 0.050 in. limit, so the joint is acceptable.

Question 48 of 54 · Suspension and Steering · 24%Not answered

A customer reports a clunking noise from the front suspension when driving over bumps. While inspecting the vehicle on a lift, the technician grabs the stabilizer bar and shakes it up and down, reproducing the noise. Which component is the most likely cause?

Explanation

Correct: Shaking the stabilizer bar loads only the bar and its links, so a clunk reproduced that way points to worn stabilizer bar links.

Incorrect: Inner tie rod ends are part of the steering linkage and are not moved by the stabilizer bar.

Incorrect: Control arm bushings move with the arm; shaking the bar does not load them much.

Incorrect: Upper strut mounts are loaded through the strut, not by shaking the stabilizer bar.

Incorrect: Lower ball joints are checked by loading the wheel and knuckle, not by moving the stabilizer bar.

Question 49 of 54 · Suspension and Steering · 24%Not answered

During a vehicle inspection, the technician pushes down on the front bumper and releases it. The vehicle oscillates up and down three times before coming to rest. What does this indicate?

Explanation

Incorrect: Sagging coil springs lower ride height; they do not keep the body from settling.

Incorrect: Broken sway bar links affect body roll in turns, not how quickly a bounce dies out.

Incorrect: Worn strut mounts clunk or bind when steering; they do not add rebound cycles.

Correct: A good strut or shock damps the bounce in about one cycle; three oscillations mean the damping is worn out.

Incorrect: Bad control arm bushings cause clunks and alignment shifts, not extra bouncing.

Question 50 of 54 · Suspension and Steering · 24%Not answered

A technician has just finished replacing several front suspension components on a vehicle. Which of the following protocols must be followed to verify the repair before returning the vehicle to the customer?

Explanation

Incorrect: A lift inspection unloads the suspension and cannot show road behavior.

Incorrect: An alignment is often needed after front suspension work, but checking it alone does not verify how the repair drives.

Incorrect: Re-checking torque is good practice, but a stationary check does not confirm the concern is fixed on the road.

Incorrect: A static visual check does not show how the parts behave under load.

Correct: A road test confirms the repair under real loads, and a re-inspection afterward catches anything that loosened or still makes noise.

Question 51 of 54 · Suspension and Steering · 24%Not answered

A technician is applying the final torque to wheel lug nuts using a manual click-type torque wrench. Which of the following methods describes the correct technique for tightening these fasteners?

Explanation

Incorrect: An impact wrench is not accurate for final wheel torque, even on a low setting.

Incorrect: A jerking motion overshoots the setting before the wrench can click, giving too much torque.

Incorrect: A cheater pipe changes the lever length and makes the setting inaccurate.

Incorrect: Pulling past the click to 'double-click' adds torque beyond the setting.

Correct: A click-type torque wrench is accurate only with a smooth, steady pull until it clicks; then the pull stops.

Question 52 of 54 · Suspension and Steering · 24%Not answered

A technician is inspecting a vehicle equipped with wear-indicator style lower ball joints. The vehicle uses a short-long arm suspension with the coil spring on the lower control arm. What is the correct method to check the condition of these joints using the indicators?

Explanation

Correct: Wear-indicator joints are checked loaded, with the vehicle's weight on the wheels; the position of the indicator shoulder in the housing shows wear.

Incorrect: Lifting by the frame with the wheels hanging unloads the joint, and wear indicators are read only under load.

Incorrect: With the joint fully unloaded the wear indicator does not show wear correctly.

Incorrect: Prying between knuckle and control arm measures play on non-indicator joints; the indicator joint is read by its shoulder instead.

Incorrect: Supporting the arm to unload the joint is the method for joints without indicators.

Question 53 of 54 · Suspension and Steering · 24%Not answered

A vehicle displays a "feathered" wear pattern across the tread of the front tires, where the ribs are smooth on one side and sharp on the other. Technician A says this is likely caused by an incorrect toe setting. Technician B says this is caused by worn shock absorbers. Who is correct?

Explanation

Correct: Technician A is right: feathering, ribs smooth on one side and sharp on the other, comes from incorrect toe scrubbing the tread sideways.

Incorrect: Technician B is wrong: worn shocks leave cupped or scalloped wear, not feathering.

Incorrect: Worn shocks do not cause feathering, so both cannot be correct.

Incorrect: Technician A names the cause correctly, so rejecting both is wrong.

Question 54 of 54 · Suspension and Steering · 24%Not answered

A technician measures a loaded lower ball joint. The manufacturer specifies a maximum axial (vertical) play of 0.050" and 0.000" radial (side) play. The joint measurements are 0.030" axial movement and 0.010" radial movement. What is the correct action?

Explanation

Correct: The axial play is within the 0.050 in. limit, but 0.010 in. of radial play exceeds the 0.000 in. allowed, so the ball joint fails and is replaced.

Incorrect: Only the axial reading is within spec; the radial play fails the specification.

Incorrect: Grease does not remove wear-related play from a worn joint, so re-measuring gives the same result.

Incorrect: A new cotter pin secures the nut but does nothing about play in the joint.

Incorrect: Tightening the castle nut beyond torque does not take up wear inside the joint.

Answer every question to see your score

Before you time yourself

Real pacing: 65 questions in 90 min, a little under a minute and a half each. 10 of them are unscored and unmarked, so a question that looks off-topic still deserves an answer. Use this page untimed first to find the area you miss most.

Question styles in the G1 guide

The six sample questions in the 2026 G1 guide (pp. 9–10) use four styles:

  • Direct question or completion: "When changing the engine oil filter, the technician should…"
  • Technician A / Technician B: two statements, then A only, B only, both or neither. Judge each statement on its own before you look at the options.
  • EXCEPT: three options are true and you pick the one that isn't. The guide flags these with a warning line.
  • Illustration: a picture of tire wear, for instance. Our questions are text only.

Three of the six samples are about tires and TPMS, which matches where the task list is heaviest.

What your score here tells you

It can't tell you whether you'd pass. Passing score: not published by ASE; note that ASE releases neither a cut score nor the questions you missed. Treat the score as a map instead. An area where you miss more than one question in three is the one to open next:

Each area page has its own question set, separate from this one.

The paid practice test from ASE

ASE sells its own G1 practice test of 28 questions, and ASE shows no price on the page. Coming from the test's owner, it's a fair final check once the area pages stop catching you out. The study guide page has a study order.

Other ASE practice tests

G1 practice, quick answers

Is there a free ASE G1 practice test?

This page is one: 54 questions with every option explained, no sign-up. The free 2026 G1 study guide also has six sample questions with answers marked.

Is there an ASE G1 practice test PDF?

The guide above is a PDF, with its six samples on pages 9–10. The questions here are on the page, not in a download, so the explanations open when you answer.

What score do I need to pass the G1?

There isn't a published one: ASE releases neither a cut score nor the questions you missed. Your report says pass or fail, so aim to understand every option here rather than to hit a percentage.

How many questions are on the real G1?

65 questions in all: 55 scored and 10 unscored, in 90 minutes. All exam facts.