Start with ASE's free 2026 G1 guide: an 11-page PDF with the test specification, 173 tasks and six sample questions. Read it as a checklist, not a textbook; it lists what you must be able to do but explains none of it. Below: where your hours pay off area by area, the guide's two counting errors, and a study order.
p. 3: who the test is for, the Spanish button, the student route and test lengths;
p. 4: the test specification, questions and percentage per area;
pp. 4–8: the task list, numbered A.1 to G.7;
pp. 9–10: six sample questions with the answers starred;
p. 11: prep resources, including the official practice tests and a free demo of the testing software.
The guide says every test question represents one or more tasks on the list, though not every task appears on every version. That makes the list your checklist.
Two counting errors in the 2026 guide
Page 3 lists G1 as "55 total/45 scored", and the table on page 4 totals "50". Neither is right: the area counts on page 4 add up to 55, and the ase.com G1 page gives 55 scored plus 10 unscored. If a book or app tells you 45, it most likely copied the guide.
Tasks per scored question
Areas differ in how many tasks share each scored question. Fewer tasks per question means each task is more likely to be asked about; more means you need breadth (guide, pp. 4–8):
Automatic transmission and HVAC: 7 tasks each for 4 questions, under 2 each. Small areas, but every task counts.
Service level, not diagnosis
Read the verbs. G1 tasks say inspect, measure, replace, adjust, bleed, refill. Brake tasks stop at verifying the ABS warning light; electrical tasks stop at meter readings, battery tests and starter draw. So for each task, the questions to ask yourself are:
What's the correct procedure, in order?
Which spec do I look up, and with what tool do I measure it?
What's the safety step: disarming the airbag, retracting an integral parking-brake piston, recovering refrigerant?
If you start answering with fault trees and scan-tool data, you're studying for A5, A6 or A8. That doesn't hurt, but it isn't where G1's points are.
A study order
Take the practice test once, untimed. The area chips show where you miss most.
Suspension and steering first. It carries 24% of the scored questions and the most tasks; wheels and tires alone are nine of them (tasks D.51–D.59).
Brakes next at 20%, drum and disc measuring especially.
Engine systems and electrical, with a meter in hand for voltage drop and current draw.
Then the small areas. Automatic transmission and HVAC have short task lists: learn every task.
Run the testing-software demo linked on page 11 of the guide, so the screen isn't new on the day.
Books, courses and the "G1 book"
Third-party G1 books and online courses are sold by several publishers. The guide's own note on them (p. 11): ASE has neither reviewed nor approved their content. Check any book against the 2026 task list and the 55 scored questions before you trust its practice tests.
ASE sells an official practice test of 28 questions, 60 days to finish it. For the whole family of tests, see the ASE study guide page.
Three questions to check yourself
0 of 3 answered · 0 correct
Question 1 of 3 · Automatic Transmission/Transaxle · 7%Not answered
Red fluid is found dripping from the crossmember area near the rear of the transmission. The fluid tracks down from the output flange yoke. Which component is the most likely cause?
Explanation
Incorrect: The manual shift shaft seal is on the side of the case at the shift linkage, away from the output yoke.
Incorrect: A pan gasket leak wets the pan rail and drips from the pan, not from the yoke.
Incorrect: A speed sensor O-ring can seep on the extension housing, but fluid would trail from the sensor, not down the yoke.
Correct: Fluid running down the output yoke comes from the seal the yoke rides in, the rear output (extension housing) seal.
Incorrect: The vent can push out fluid when the unit is overfilled, but it sits on top of the case, not at the yoke.
Question 2 of 3 · Manual Drive Train and Axles · 11%Not answered
A technician is reassembling a two-piece driveshaft after performing service. To prevent driveline vibration and ensure proper operation, how must the U-joint yokes be oriented in relation to each other?
Explanation
Incorrect: Random orientation ignores phasing and almost always causes vibration.
Incorrect: A forty-five-degree offset is also out of phase and causes vibration.
Incorrect: Offsetting the yokes by ninety degrees puts the U-joints out of phase and doubles the speed fluctuation.
Incorrect: Yoke orientation is set relative to the other yoke, not perpendicular to the flanges.
Correct: Yokes on the same shaft are kept in phase, aligned in the same plane, so the speed changes of one U-joint cancel those of the other.
Question 3 of 3 · Suspension and Steering · 24%Not answered
Technician A says that a new cotter pin must be used whenever a castle nut is removed for service. Technician B says that prevailing torque (nylon insert) nuts on suspension parts can always be reused if the insert looks intact. Who is correct?
Explanation
Correct: Technician A is right: a cotter pin is bent to lock and fatigues when straightened, so a new pin goes in every time; Technician B overstates nut reuse.
Incorrect: Technician B is wrong: many manufacturers require new prevailing torque nuts, because the insert loses grip after use even when it looks fine.
Incorrect: Technician B's 'always reuse' rule conflicts with manufacturer instructions, so both cannot be correct.
Incorrect: Technician A's new-cotter-pin rule is correct, so rejecting both is wrong.
Answer every question to see your score
G1 study, quick answers
Is there an ASE G1 study guide PDF?
Yes, free from ASE: the 2026 G1 study guide, 11 pages with the task list and six sample questions. No sign-up is needed to download it.
What is on the ASE G1 test?
Seven areas: engine systems, automatic transmission, manual drive train and axles, suspension and steering, brakes, electrical, and HVAC. Suspension and steering is the largest at 13 of 55 scored questions.
Do I need a G1 prep book?
No book is required. The free guide gives the task list; a book helps if it explains procedures you don't do at work. ASE hasn't reviewed any third-party prep.