ASE Updates Electronic Diesel Engine Diagnosis Specialist (L2) Test

Dec. 6, 2019

The National Institute for Automotive Service Excellence (ASE) will release an updated version of the Electronic Diesel Engine Diagnosis Specialist (L2) test on Jan. 6, 2020.

The updated test will feature the new Composite Vehicle Type 4 (CV4), a generic medium/heavy vehicle equipped with a high-pressure common rail (HPCR) diesel fuel system, an updated exhaust aftertreatment system, and other updated systems and controls.

As is true of the current test, some questions will call for use of the composite vehicle reference. The updated test will use the L2 Composite Vehicle Type 4 (CV4) Reference Booklet, which may be downloaded or requested (printed copy) at no cost from along with the updated L2 study guide.

Test takers will receive a booklet at the testing center for use during the test but should acquire and carefully review a copy prior to the test appointment.

"As technology changes, the ASE tests must also change to remain relevant. This update has been a major undertaking for our test development department over the past 2 years," says Tim Zilke, ASE CEO and president. "We are grateful to the many subject matter experts who have contributed their knowledge to updating and improving the test and the reference booklet."

Test takers need to be aware of some important differences during rollout of the updated test in the first half of 2020. From January to July of 2020:

  • L2 certification and recertification tests will consist of 75 questions and have a 180-minute (3-hour) time limit.
  • Test takers will receive an immediate "notice of completion" rather than a pass/fail score report. Their myASE profile will show "Score Pending" for the test.
  • Official pass/fail test results for all L2 certification and recertification tests will be released through myASE accounts in June 2020.

Starting in July, the L2 (certification) test will have 55 questions (including 10 unscored research questions). The L2R (recertification) test will have 45 questions. Both tests will have a 2-hour time limit and will provide immediate pass/fail test results.

The current Electronic Diesel Engine Diagnosis Specialist (L2) test, with Composite Vehicle Type 3 (CV3), will be administered to test takers through January 5, 2020. Technicians who will need test results before mid-2020 are encouraged to register and schedule their testing session now.

The National Institute for Automotive Service Excellence (ASE) was founded in 1972 as a non-profit, independent organization dedicated to improving the quality of automotive service and repair through voluntary testing and certification of automotive professionals. Approximately a quarter of a million ASE Certified automobile, truck, and collision repair technicians, and parts specialists work in dealerships, independent shops, service stations, auto parts stores, fleets, schools, and colleges across the nation.

For more information about ASE, visit