This free ASE G1 study guide teaches to the certification test — every content area the National Institute for Automotive Service Excellence tests, organized the way the exam is built.[1] G1 is a broad, entry-level test: it touches all seven vehicle systems at a and depth, not the specialist depth of the A-series.
The computer-based test has 65 questions (55 scored, 10 unscored research items) and 90 minutes of testing time, spread across seven content areas.[2] Questions are written by working technicians and focus on practical service and diagnosis, often using the format. This guide is interactive, not a wall of text — each area has a built-in checkpoint quiz, hover-able glossary terms, worked scenarios, and concept questions.
Read this guide content area by content area, test yourself at each checkpoint, then round out your free G1 prep with our practice questions and flashcards.
ASE G1 is one of the 29 ASE certifications — explore our ASE study guides to compare and prep across the whole family.
ASE G1 Exam Snapshot
| Detail | ASE G1 Auto Maintenance & Light Repair |
|---|---|
| Questions | 65 administered (55 scored + 10 unscored research) |
| Time | 90 minutes of testing |
| Format | Multiple choice, computer-based by appointment (Prometric) |
| Content areas | 7 (Suspension & Steering and Brakes are the largest) |
| Passing score | Scaled score; standard set per test by an expert panel (no fixed %) |
| Experience | ~1 year of relevant work experience (entry-level scope) |
| Cost | 34 registration fee per order (fees can change) |
| Certification cycle | Valid 5 years; recertify via the G1 recertification test |
| Certifying body | ASE (National Institute for Automotive Service Excellence) |
G1 is broad, not deep— it touches all seven systems at the level a maintenance & light-repair technician works, not the depth of the A-series specialist tests.
Because Suspension & Steering and Brakes together make up nearly half of the scored test, focus your time there first — but G1 rewards broad familiarity across every system.[1] Here is the official distribution of the 55 scored questions:
Suspension & Steering and Brakes together are nearly half of the scored test — but G1 spans every system at a maintenance and light-repair depth.
This guide teaches all seven content areas as seven study modules. Before the areas, it helps to picture how a maintenance and light-repair service actually flows:
- 1 · Read the service scheduleLook up the manufacturer's maintenance schedule for the mileage/time interval — it is the authority for what is due.
- 2 · Verify the concern (if any)If the customer reports a symptom (noise, pull, smell), confirm and reproduce it before condemning a part.
- 3 · Inspect and measureCheck fluid levels and condition, tire tread and pressure, brake pad thickness, belts, hoses, and the battery.
- 4 · Service or light-repairChange due fluids and filters, rotate tires, replace worn pads/shocks/bulbs/hoses — to spec and torque.
- 5 · Confirm and documentReset oil-life/maintenance reminders, relearn TPMS if needed, road-test, and record the work performed.
Follow the maintenance schedule, measure before you replace, and always reset reminders and relearn systems (TPMS) after the service.
1 · Engine Systems
About 16% of the scored test (9 questions). G1 engine work is maintenance and light repair: keeping the engine serviced and recognizing common drivability faults — not the deep teardown of the A1 specialist test.[1]
Oil, Filters & Viscosity
The most common engine service is the oil and filter change. Check oil on level ground with the engine off, change it per the or maintenance schedule, and use the specified (e.g. 5W-30): the W number is cold flow, the second number is hot protection.
Always use the manufacturer-specified fluid and interval — the maintenance schedule, not a rule of thumb, is the authority.
Cooling, Belts & Hoses
Check level cold at the reservoir and use the correct type. The stuck closed overheats the engine; stuck open keeps it too cool. Inspect the for cracks, glazing, and rib wear, and check the — a squeal usually means a slipping belt or weak tensioner.
| Finding | What it points to |
|---|---|
| Oil low and dark/dirty | Overdue oil change or oil consumption; service per the schedule |
| Coolant low / overheating | Leak, stuck thermostat, weak radiator cap, or failed water pump |
| Belt squeal | Slipping serpentine belt or a weak/worn tensioner |
| Oil in the coolant | Often a leaking head gasket — refer for deeper repair |
| Rough idle, weak power | Worn or fouled spark plugs — a routine maintenance item |
Ignition, Fuel & Emissions
Worn or fouled spark plugs cause rough idle, hesitation, and poor economy; long-life iridium plugs are commonly replaced near 90,000–100,000 miles (always confirm in the schedule). The keeps the mixture near 14.7:1, and the cleans the exhaust.[5] A flashing check-engine light warns of a converter-damaging misfire — stop and diagnose.
Checkpoint · Area 1 · Engine Systems
Question 1 of 10
During a cylinder compression test, Technician A says that if all cylinders read low compression, it could indicate a timing issue. Technician B says that it could be due to a widespread gasket failure. Who is correct?
2 · Automatic Transmission/Transaxle
About 7% of the scored test (4 questions). At the G1 level this is fluid service and recognizing common shift complaints — checking the and knowing when to refer a deeper transmission job.[1]
Fluid Level & Condition
The first check for almost any automatic-transmission complaint is fluid level and condition. Low fluid causes slipping and delayed engagement; a burnt smell or very dark fluid signals overheating. Check by the manufacturer’s method — some units are sealed and checked at a specified temperature, not with a dipstick — and always use the specified ATF.
Shift Symptoms & Service
Early, soft shifts often trace to low fluid pressure; harsh or erratic shifts can come from a pressure-control solenoid; and slipping in a specific gear points to worn clutches or bands. A whining noise and delayed engagement together can mean a restricted transmission filter.
Checkpoint · Area 2 · Automatic Transmission/Transaxle
Question 1 of 10
A vehicle with an automatic transmission experiences no movement in any gear. What is the FIRST thing a technician should check?
3 · Manual Drive Train & Axles
About 11% of the scored test (6 questions). This area covers the clutch and manual gearbox, drive axles and , the driveshaft, and the — inspection and common symptoms.[1]
Clutch & Manual Gearbox
Difficulty shifting into all gears often means the clutch is not fully releasing — commonly air in a hydraulic clutch system. A grinding shift into reverse can be a faulty reverse idler gear (reverse usually has no synchronizer), and a manual that pops out of gear suggests worn synchronizers. A high-pitched whine only with the clutch engaged points to a worn .
CV Joints, Driveshaft & Differential
Inspect at every service — a torn boot lets grease out and grit in, and a clicking noise during tight turns means a failing CV joint. On a rear-wheel-drive car, a vibration that increases with speed can be a bent driveshaft, and metal flakes in the fluid usually mean failing bearings.
Checkpoint · Area 3 · Manual Drive Train & Axles
Question 1 of 10
When a technician is unable to shift into any gear with the engine running, but can do so when the engine is off, what should be checked FIRST?
4 · Suspension & Steering
About 24% of the scored test (13 questions) — the single biggest area. This covers shocks and struts, springs, ball joints, the steering system, wheel alignment, tires, and TPMS.[1]
Shocks, Struts & Suspension
Shocks and struts (often a up front) damp ride motion; worn ones cause bouncing, nose-dive, and poor handling. A clunk over bumps usually points to worn , control-arm bushings, or sway-bar links. A vehicle sitting low at one corner or the rear can mean a sagging or broken spring.
Steering & Ball Joints
Hard steering at low speed can be a weak power-steering pump or low fluid; excessive steering play often traces to worn tie-rod ends. A worn is both a safety item and a cause of uneven tire wear and a clunk. An off-center steering wheel when driving straight can be a bent tie rod or an alignment that was never set.
Alignment, Tires & TPMS
The three alignment angles each do something different:
Memory aid: toe wears tires fastest, camber wears one edge, and caster controls straight-line stability and steering return.
on the schedule for even wear, inflate to the door-jamb placard pressure (not the sidewall maximum), and check pressure cold. After any tire service, the may need a relearn so it reports the correct wheel.
| Wear pattern | Likely cause |
|---|---|
| Both edges worn | Under-inflation (or hard cornering) |
| Center worn | Over-inflation |
| One edge worn | Camber out of spec (or worn ball joint/bushing) |
| Feathered / saw-tooth | Incorrect toe |
| Cupping / scalloping | Worn shocks/struts or other suspension wear |
Checkpoint · Area 4 · Suspension & Steering
Question 1 of 10
What would be the most likely cause of an intermittent clunking noise from the front suspension when driving over bumps?
5 · Brakes
About 20% of the scored test (11 questions) — the second-biggest area. Brake work is core light repair: pads, rotors, shoes, drums, hydraulics, fluid service, and basic ABS.[1]
Hydraulics & Brake Fluid
The sends pressurized fluid to all four wheels. A soft, spongy pedal usually means air in the system (bleed it); a pedal that slowly sinks can be a failing master cylinder. is hygroscopic — it absorbs moisture, which lowers its boiling point — so keep it capped and change it on schedule.
Pads, Rotors, Shoes & Drums
A high-pitched squeal at light braking is the telling you the pads are thin. A pulsation in the pedal means a warped or thickness-varied . Replace pads as a set per axle, and measure rotor thickness against the minimum (discard) spec. Many rear axles use with shoes.
| Symptom | Likely cause |
|---|---|
| Squeal at light braking | Worn pads — the wear indicator is contacting the rotor |
| Pulsation in the pedal | Warped or thickness-varied rotor |
| Soft / spongy pedal | Air in the hydraulic system — bleed the brakes |
| Pedal slowly sinks | Failing master cylinder (internal leak) |
| Very hard pedal | Failed brake booster or lost vacuum |
| Pull to one side | Sticking caliper on the opposite side |
Power Assist & ABS
The multiplies pedal force; if it fails, the pedal gets very hard. The pulses pressure to keep wheels from locking and preserve steering. ABS faults set a separate ABS warning light — and the first diagnostic step is to scan for ABS codes, not to start replacing sensors.
Checkpoint · Area 5 · Brakes
Question 1 of 10
What could be the cause of a vehicle pulling to one side when braking?
6 · Electrical
About 15% of the scored test (8 questions). G1 electrical is battery and charging service, starting-system basics, and reading simple circuits — including the .[1]
Battery & Charging
Battery service means cleaning corroded terminals, securing the hold-down, and load- or conductance-testing state of health. The should charge the battery at roughly 13.5–14.5 volts running. A battery warning light with the engine running means a charging fault, and headlights that dim as RPM drops at idle suggest a failing alternator.
Starting & Circuits
Slow cranking with a known-good battery usually means high resistance in the circuit — corroded or loose cables and grounds. The finds it: a reading above about 0.1 volt on a ground or feed reveals unwanted resistance that an ohmmeter check would miss because the test is done under load.
Checkpoint · Area 6 · Electrical
Question 1 of 10
A vehicle's headlights dim when the RPMs drop at idle. The MOST likely cause of this is:
7 · Heating, Ventilation & Air Conditioning
About 7% of the scored test (4 questions). At the G1 level this is HVAC service and common complaints — cabin air filter, airflow, basic A/C operation, and heating — with refrigerant handled per regulations.[1]
A/C Operation & Service
An A/C system circulates to move heat from the cabin to the outside; refrigerant must be recovered, never vented. Poor cooling with bubbles in a sight glass can mean a low charge; a musty odor on startup is mold or mildew on the evaporator, often made worse by a clogged or a blocked evaporator drain.
Heating & Airflow
Cabin heat comes from the , warmed by engine coolant. A sweet antifreeze smell with foggy windows points to a leaking heater core. Weak airflow on all settings is a classic clogged-cabin-filter symptom; replacing that filter is routine maintenance.
Many ASE G1 items give two technicians’ statements and ask who is right. Judge each statement separately as true or false, then map to the answer:
The trap is letting a true statement A make you ignore a false statement B. Evaluate both before you choose.
Checkpoint · Area 7 · Heating, Ventilation & A/C
Question 1 of 10
When diagnosing an A/C system that is not cooling properly, the technician finds that the compressor clutch engages, but the low-side pressure is high and the high-side pressure is low. This could indicate:
How to Use This Study Guide
A study guide is a map, not the whole territory — use it alongside hands-on shop experience and our free tools. Because G1 is broad, weight your time by the content areas: spend the most on Suspension & Steering and Brakes, then Engine Systems and Electrical. Read every item carefully, judging each statement on its own before you answer.
- 1
Read a content area here
Work through one area at a time — start with the heaviest, Suspension & Steering and Brakes.
- 2
Take the checkpoint
The quick check at the end of each area exposes what didn't stick.
- 3
Drill the gaps
Send your weak area straight into the free practice questions and flashcards.
- 4
Test under exam conditions
Take full, timed practice sets and review every miss — especially the diagnostic reasoning.
ASE G1 Concept Questions
Common maintenance and light-repair concepts the G1 test actually measures — at least one per content area. Tap any card for a short, exam-ready answer backed by an authoritative source, then test yourself on them as flashcards.
ASE G1 Glossary
Quick definitions for the terms you’ll see most across the ASE G1 Auto Maintenance & Light Repair test:
- Alternator
- The belt-driven generator that charges the battery and powers electrical loads while the engine runs, typically 13.5–14.5 volts.
- Antilock braking system (ABS)
- A system that pulses brake pressure to keep wheels from locking during hard braking, preserving steering control. Faults set a separate ABS warning light.
- ASE G1
- The ASE Auto Maintenance and Light Repair certification test, a broad entry-level exam from the National Institute for Automotive Service Excellence that spans all major vehicle systems at a maintenance and light-repair depth.
- Automatic transmission fluid (ATF)
- The specified fluid that an automatic transmission uses for hydraulic control, lubrication, and cooling. Low or burnt ATF causes slipping and harsh shifts.
- Ball joint
- A pivoting suspension/steering connection between the control arm and steering knuckle. A worn ball joint causes a clunk over bumps and uneven tire wear.
- Belt tensioner
- A spring-loaded pulley that keeps the correct tension on the serpentine belt. A weak tensioner causes belt squeal and slipping.
- Brake booster
- A vacuum- or hydraulically-assisted unit that multiplies pedal force. A failed booster makes the pedal very hard to press.
- Brake drum & shoes
- The drum-brake friction system used on many rear axles: brake shoes press outward against a rotating drum to slow the wheel.
- Brake fluid (DOT)
- A hygroscopic hydraulic fluid (DOT 3, 4, or 5.1) that transmits pedal force to the brakes. Because it absorbs moisture, its boiling point drops over time, so it is changed periodically.
- Brake pad wear indicator
- A small metal tab on a brake pad that contacts the rotor when the pad wears thin, producing a squeal that warns the driver to replace the pads.
- Brake rotor (disc)
- The spinning disc a disc brake's pads clamp to stop the wheel. A warped or thickness-varied rotor causes a pedal pulsation.
- Cabin air filter
- A filter that cleans air entering the passenger compartment. When clogged, it reduces vent airflow and can cause odors. It is a routine maintenance replacement.
- Camber
- The inward or outward tilt of a wheel viewed from the front. Excessive camber wears one edge of the tire.
- Caster
- The forward or rearward tilt of the steering axis viewed from the side. It controls straight-line stability and steering return, not tire wear.
- Catalytic converter
- An exhaust device that converts carbon monoxide, hydrocarbons, and oxides of nitrogen into less harmful carbon dioxide, water, nitrogen, and oxygen.
- Constant-velocity (CV) joint
- A flexible joint on a drive axle that transmits power to the wheels while allowing for steering and suspension movement. A torn CV boot leads to joint failure and a clicking noise on turns.
- Coolant (antifreeze)
- A water-and-glycol mixture that transfers engine heat and protects against freezing and corrosion. A 50/50 mix typically protects to about −34°C (−29°F).
- Differential
- A gearset that lets the drive wheels on an axle turn at different speeds, which is necessary in a turn since the outer wheel travels farther than the inner.
- Heater core
- A small radiator that uses hot engine coolant to warm cabin air. A leaking heater core causes a sweet antifreeze smell and foggy windows.
- Light repair
- Common, lower-complexity repairs a maintenance technician performs, such as brake pads, shocks and struts, batteries, bulbs, hoses, and filters.
- MacPherson strut
- A combined shock absorber and suspension upright that also serves as a steering pivot, common on the front of front-wheel-drive vehicles.
- Maintenance
- Routine, scheduled service that keeps a vehicle healthy — fluid and filter changes, tire rotation, belt and hose inspection, and following the manufacturer's maintenance schedule.
- Maintenance schedule
- The manufacturer's published list of services and the mileage or time intervals at which they are due. It is the authority for what maintenance to perform and when.
- Master cylinder
- The hydraulic pump operated by the brake pedal that sends pressurized fluid to all four wheels.
- Oil viscosity (SAE)
- Oil's resistance to flow, rated by the Society of Automotive Engineers. In a multigrade like 5W-30, the first number with the W is the cold-flow rating and the second is the thickness at operating temperature.
- Oil-life monitor
- A system that estimates remaining oil life from engine operating data and signals when an oil change is due, replacing a fixed-mileage interval on many vehicles.
- Oxygen sensor
- A sensor in the exhaust that reports whether the mixture is rich or lean so the computer can keep the air-fuel ratio near the ideal 14.7:1.
- Pilot bearing
- A small bearing that supports the transmission input shaft where it enters the crankshaft on a manual-transmission vehicle.
- Refrigerant
- The fluid (such as R-1234yf or R-134a) an A/C system circulates to absorb heat in the cabin and release it outside. It must be recovered, never vented.
- Serpentine belt
- A single multi-ribbed belt that drives several engine accessories — alternator, A/C compressor, power-steering pump, and often the water pump — routed around an automatic tensioner.
- Starter motor
- The electric motor that cranks the engine to start it, drawing high current through the starter circuit and solenoid.
- Technician A / Technician B
- The signature ASE question format presenting two statements; you decide whether A only, B only, both, or neither is correct.
- Thermostat
- A temperature-controlled valve that blocks coolant flow to the radiator until the engine warms, then opens to hold operating temperature. Stuck closed = overheating; stuck open = runs too cool.
- Tire rotation
- Moving tires between positions on the vehicle to even out wear and extend tire life.
- Toe
- Whether the fronts of the tires point inward (toe-in) or outward (toe-out). Incorrect toe is the most common cause of feathered tire wear.
- TPMS
- Tire Pressure Monitoring System — warns the driver of significant under-inflation. Many vehicles need a relearn procedure after tire service.
- Voltage-drop test
- A test that measures voltage lost across a connection or cable under load. A high drop (above about 0.1 V on a ground) reveals unwanted resistance from corrosion or a bad connection.
Free ASE G1 Study Materials & Resources
Everything you need to prepare for the ASE G1 test is free here — no paywall, no sign-up. This guide is the foundation; pair it with the rest of our free G1 study materials for active recall, timed practice, and last-minute review:
- ASE G1 Practice Test — exam-style questions across all seven content areas, with explanations.
- ASE G1 Flashcards — active-recall decks for the components, procedures, and specs you must know cold.
ASE G1 Study Guide FAQ
The ASE G1 Auto Maintenance and Light Repair test has 65 multiple-choice questions and 90 minutes of testing time. Of the 65, 55 are scored and 10 are unscored research questions ASE is trying out for future tests; they are not identified, so answer every question.
ASE G1 covers seven content areas: Engine Systems (9 scored questions), Automatic Transmission/Transaxle (4), Manual Drive Train and Axles (6), Suspension and Steering (13), Brakes (11), Electrical (8), and Heating, Ventilation, and Air Conditioning (4). Suspension and Steering plus Brakes together are nearly half the test.
G1 is a single, broad entry-level test that covers every vehicle system at a maintenance and light-repair depth — what a maintenance technician does day to day. The A-series tests (A1–A9) each cover one system in much greater depth for a specialist. G1 is wide but not deep.
There is no fixed percentage. Raw scores are converted to a scaled score, and a panel of automotive subject-matter experts sets the passing standard for each test form so the bar stays consistent even as question difficulty varies. Your overall scaled score, not any single content area, decides pass or fail.
The G1 test is computer-based and delivered by appointment at a Prometric testing center. You register through your myASE account, schedule the appointment, and typically have 90 days from purchase to test. If you fail, you must wait 30 days before retaking and pay the test fee again.
ASE requires about one year of relevant hands-on work experience to earn the G1 certificate (less than the two years typical of the A-series tests, reflecting its entry-level scope). You may pass the test first; ASE holds your result and issues the certification once you document the required experience.
ASE G1 certification is valid for five years. You recertify by passing the shorter current G1 recertification test before your certification expires, keeping your maintenance and light-repair credential current.
It is the signature ASE format: two technicians each make a statement, and you choose whether Technician A only is correct, Technician B only, both, or neither. Judge each statement separately as true or false, then pick the answer that matches — do not let a true statement A make you overlook a false statement B.
Work through the seven content areas, spending the most time on Suspension and Steering and Brakes since together they are nearly half the scored test. After each area, take the checkpoint quiz to find gaps, drill them with our free practice questions and flashcards, and revisit the diagrams and worked scenarios before test day.
Yes — the full guide, the checkpoints, the glossary, the practice questions, and the flashcards are 100% free, with no account required.
References
- 1.ASE (National Institute for Automotive Service Excellence). “G1 Auto Maintenance and Light Repair Certification Test.” ASE. ↑
- 2.ASE. “The Official ASE Study Guide — Auto Maintenance and Light Repair (G1).” ASE. ↑
- 3.ASE. “Dates, Fees & Test Times.” ASE. ↑
- 4.ASE. “myASE Account & Test Registration.” ASE. ↑
- 5.U.S. Environmental Protection Agency. “Transportation, Air Pollution & Emission Controls.” U.S. EPA. ↑
Sources for the concept answers
Every answer in the ASE G1 concept questions above is drawn from an authoritative primary source:
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