1.1 Current Exam Facts

What A9 certifies

The National Institute for Automotive Service Excellence (ASE) A9 Light Vehicle Diesel Engines test is the Automobile & Light Truck specialty for diesel engines in light vehicles: passenger cars, sport-utility vehicles (SUVs), and light trucks through Class 3. That is the shop population that actually rolls in for this work—a Ford Power Stroke 6.7-liter Super Duty, a General Motors Duramax L5P in a 2500 pickup, a Ram Cummins 6.7-liter, a Jeep or Ram EcoDiesel, or a Volkswagen Turbocharged Direct Injection (TDI) car. The credential tells a shop, a fleet, or a customer that you can diagnose and repair those engines across fuel, air, aftertreatment, lubrication, cooling, and the mechanical top and bottom end.

A9 sits in the A-series family and is a general test, not an L-level advanced test. Delivery is computer-based at Prometric. A1 through A9 carry a Spanish option that you use during the test, not at registration: a Leer en español button opens a side-by-side Spanish/English rendering of the question and answer choices. ASE states that no special registration process is needed, and you still mark your answer on the English side. This OpenExamPrep chapter is independent prep covering the published A9 content areas. It is not an ASE publication and does not claim official approval, review, or partnership.

What A9 is not

Two nearby credentials cause most of the scheduling mistakes:

• A9 is not required for ASE Master Automobile Technician. Master Automobile status is A1 through A8. A gasoline-only Master technician can hold that credential without ever sitting A9. A diesel specialist can hold A9 without being a Master. Do not buy A9 because you think the blue Master seal is incomplete without it.
• A9 is not ASE T2 Medium/Heavy Truck Diesel Engines. T2 belongs to the medium/heavy truck series and is built around Class 4–8 engines, vocational duty cycles, and truck-shop procedures. Charge-air coolers and diesel particulate filters appear in both worlds, but A9 examples stay in light-duty packaging, sensors, and control strategies. Passing A9 does not certify a Class 8 highway tractor the way T2 does.
• A9 is not a manufacturer brand cert. It does not replace Ford, GM, Stellantis, or Volkswagen factory diesel training, calibration access, or special tools. Brand service information still governs the repair in the bay.

Write those three limits on the same card as the question count. Technicians who study T2 Class 8 regeneration playbooks and skip pickup-truck diesel exhaust fluid (DEF) tanks, car-platform glow-plug modules, and light-duty charge-air routing will miss the A9 fence.

Published 2026 length, timing, and on-screen count

ASE's A1–A9 test page is the source for the numbers you will pace against:

The initial sitting therefore puts about 60 items on the screen: 50 that count plus about 10 research items ASE is evaluating. You cannot see which is which. Recertification is the short form and does not add that research block. If you use the full 75 minutes on about 60 items, you have roughly 75 seconds per item. Direct questions should take less. Technician A / Technician B stems and EXCEPT stems take more. Flag and move; do not spend four minutes rereading one stem while unanswered items sit at the end.

Those 50 scored questions are the real exam length. They are not the size of any third-party practice bank, including the independent OpenExamPrep bank. Practice inventory is optional rehearsal. The live test is 50 scored items in 75 minutes at Prometric.

Fees, the 90-day purchase window, and 2026 seasons

ASE's 2026 register-now page publishes a two-line fee, not a single mystery number:

• $34 registration fee per order. One registration charge covers the tests in that order.
• $62 general test fee for A9. A9 is a general test, so it uses the general-test price, not an L-level price.

Recertification general tests are also $62. A-series technicians who keep credentials current through the ASE Renewal App pay $52 annually when they use that product instead of sitting every written recert. Confirm the live cart in your ASE account before you pay; this chapter uses the 2026 published figures rather than older catalog numbers that still float around shop talk.

You have 90 days from purchase to take the test. Miss that window and you repurchase. ASE runs year-round windows in 2026:

Book Prometric early if Saturday seats at your nearest center disappear. Bring the identification ASE and Prometric list in the confirmation mail. You will not receive a paper booklet. There is no separate Spanish form to select at registration; the Spanish rendering is the on-screen Leer en español button described in Section 1.2.

Experience, testing early, and the held certificate

ASE Need to Know © 2026 and the work-experience page require two years of relevant hands-on repair technician experience for A1–A9 certification. Formal education can substitute for part of that time, and how much depends on the program. Completing an ASE-accredited training program, or passing three or more ASE Entry-Level Certification tests, credits 1 year toward the 2-year requirement. Other training credits up to 1 year, at 2 months of full-time training (or 200 program hours) per month of credit. An ASE-accredited OEM-sponsored co-op program credits the full 2 years. Those substitutes cannot be combined—take the one that applies, then document hands-on time for whatever is left. You may test before the experience is approved. If you pass, ASE holds the certification until the experience documentation is accepted. That is why an apprentice can sit A9 during a busy season and still need the shop's experience affidavit before the certificate is released.

Relevant experience means diesel diagnosis and repair you actually performed. Time on Duramax no-starts, Power Stroke fuel-system diagnosis, Cummins aftertreatment, EcoDiesel oil-dilution complaints, and TDI charge-air leaks matches the credential. Gasoline-only A1 or A8 time builds shared engine skill, but it does not by itself prove light-vehicle diesel experience. Watching videos is not hands-on time.

Recertification every five years

ASE certifications expire on a five-year cycle. To keep A9 current you either pass A9R—25 scored questions, 30 minutes, $62 general recert fee plus any registration that applies—or you use the ASE Renewal App path ASE offers for A-series credentials at $52 per year. Recertification is how working technicians stay current as common-rail pressures, variable-geometry turbocharger (VGT) actuators, and selective catalytic reduction (SCR) systems change. Do not wait until the last month of year five if your nearest Prometric site is a long drive.

Scoring in one planning sentence

ASE scores A9 with a criterion-referenced standard set by ASE. ASE does not publish a single passing percentage. Section 1.2 covers formats, research items, and score reports. For calendar planning, treat every content area as able to move you across the cut—especially Fuel System and Air Induction and Exhaust, which together are half the scored items.

Logistics card to keep next to the study calendar

• 50 scored / 75 minutes initial; about 10 unlabeled research items on that sitting only
• A9R: 25 scored / 30 minutes
• $34 per order + $62 general test; 90 days to sit; 2026 windows listed above
• 2 years hands-on; an ASE-accredited program or 3+ entry-level tests credit 1 year, an OEM-sponsored co-op credits 2; test-early / hold-until-approved is allowed
• Recertify every 5 years; Renewal App is $52 per year for A-series when you use that path
• Prometric computer-based; A1–A9 offer an in-test Leer en español side-by-side rendering, no special registration needed
• Not a Master Automobile requirement; not T2; light vehicles through Class 3