ASE G1 Practice Test — Free Maintenance & Light Repair
The ASE G1 test covers maintenance and light repair across every major system, which makes it the entry point for new technicians and students. It's broad but shallow — basic service judgment, not deep diagnosis. The worked questions below cover tire wear, brake service limits, and fluid checks the way G1 asks them, then point you to the free practice app.
What G1 is — and who takes it
G1 Auto Maintenance & Light Repair spans the basics of every system: engine, brakes, steering and suspension, electrical, HVAC, drivetrain, and routine service. It’s the lowest-barrier ASE credential and a common starting point for students and first-year techs. It does not count toward Master Automobile (A1–A8), but it’s a real, recognized certification — see the certification guide for how it fits a career path.
Worked G1 questions
1. Tire wear. A tire shows wear on both outer edges with the center tread still good. Most likely cause?
- Answer: Underinflation. Low pressure lets the tire ride on its shoulders, wearing both outer edges. Overinflation does the opposite — center wear. Wear on only one edge points to a camber or toe alignment issue, not pressure.
2. Brake service. During a brake inspection you find the pads worn down to the wear indicator, which is just contacting the rotor. What’s the correct action?
- Answer: Replace the pads (and service the rotors to spec). The wear indicator contacting the rotor is the designed signal that the pads have reached their service limit. Don’t return the vehicle to service on indicator-worn pads; measure the rotors against the manufacturer’s minimum thickness and machine or replace as needed.
3. Engine oil check. A customer’s engine is one quart low; the oil on the dipstick is dark but smooth, with no grit or milkiness. At a maintenance level, what’s the right call?
- Answer: Top off to the full mark (or change per the service interval). Dark oil alone is normal — oil darkens as it does its job. There’s no sign of coolant (milky) or metal (grit), so this is routine top-off or a scheduled change, not a diagnosis. Note the consumption and recheck at the next service.
A worked question
During a routine brake inspection, a technician finds the front pads at 2 mm of lining thickness and the rotor at exactly the manufacturer's minimum discard thickness. Technician A says the pads must be replaced. Technician B says the rotors must be replaced. Who is right?
- A Technician A only
- B Technician B only
- C Both A and B✓ correct
- D Neither
Both answers are right. Pads at 2 mm are at or below the service limit and need replacement. A rotor at minimum discard thickness cannot be machined — any metal removed would take it below discard, which is unsafe. Replace both. Both A and B are correct.
Exam trap: G1 tests safe service judgment: the pads are at or below a typical service limit (most specs call for replacement at 2–3 mm), and a rotor that is already AT minimum discard thickness has no metal left for machining — it cannot be turned and must be replaced. Both answers are correct, and the G1 task list explicitly covers knowing when to replace versus resurface.
Quick check
A tire shows wear across both outer edges but the center tread is still good. The most likely cause is:
Reading your result
Because G1 is broad, your misses will usually point to whole systems you’re rusty on — brakes, electrical, HVAC — rather than fine details. Study those systems at a basic level, get consistently above ~80%, then start free ASE practice. Planning to go further? Try the A5 Brakes practice test or the A1 Engine Repair practice test as your next step, map the full path on the A-series prep page, or browse all ASE practice tests.