ASE Cheat Sheet 2026

The 30 highest-yield ASE facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. Why should paint be strained before being poured into the spray gun cup? → To remove lumps and debris that could clog the gun or mar the finish
2. When receiving a shipment, what should you do before stocking the parts? → Verify quantities and part numbers against the packing slip
3. A diesel engine cranks but will not start. Which should be checked first? → Fuel supply and filters
4. A hazardous fluid leak is found during inspection. The consultant should: → Inform the customer of the safety concern and recommend action
5. Before lifting a vehicle on a frame-contact lift, the most important step is to: → Position the lift pads at the manufacturer's designated lift points
6. A vehicle has a P0171 (System Lean, Bank 1) code. The long-term fuel trim (LTFT) for Bank 1 is +22%. The MOST likely cause is: → A vacuum leak or MAF sensor underreporting air mass on Bank 1
7. On a common rail diesel, which component maintains fuel pressure in the rail between injection events? → The fuel rail accumulator volume and pressure limiter valve
8. What does a 'snow plow' headgear receiver hitch installation require for proper electrical operation? → A correctly wired control harness and adequate vehicle charging capacity
9. Cratering or pinholing in primer-surfacer over body filler often results from: → Air pockets or pinholes in the filler not being properly filled
10. In the context of ase-certified mechanics, which principle most directly governs engine performance & diagnostics practices? → Applying evidence-based methodologies with peer-reviewed support
11. A technician finds 12.6 volts at rest and 14.2 volts with the engine running. This indicates: → A properly charging system
12. A relay has terminals 85, 86, 87, and 30. Which two terminals are the control (coil) side? → 85 and 86
13. An engine exhibits excessive oil consumption with blue smoke from the exhaust that is WORST on deceleration. What is the MOST likely cause? → Worn or damaged valve stem seals
14. What does toe-in mean in wheel alignment? → The front of the tires are closer together than the rear when viewed from above
15. What is the purpose of crosshatching cylinder walls during honing? → To create an oil retention pattern that aids ring seating
16. An idle vacuum test is carried out by a technician. The 2001 Sedan's test results show a pressure of 11 in. Hg. What should the technician check next? → Check for proper timing
17. After replacing a CNG component, what verification step is essential before returning the vehicle? → Pressurize and perform a leak test on all disturbed fittings
18. When refueling a CNG vehicle, the temperature compensation matters because: → Gas heats up during fast fill, so the tank may read full before reaching true capacity
19. Which system uses CAN bus communication? → Modern electronic control systems
20. What is the function of the exhaust gas recirculation (EGR) system in a diesel engine? → Reduce NOx emissions by lowering combustion temperature
21. Which of the conditions listed below can cause brake pedal fade? → Brake drum machined beyond its limit
22. A refrigerant recovery/recycling/recharging machine must be used when servicing an A/C system after a collision because: → Federal law prohibits venting refrigerants into the atmosphere
23. Which type of blower motor speed control uses a variable resistance to reduce voltage to the motor at lower speed settings? → Resistor block
24. What does a high reading on both the high-side and low-side A/C gauges MOST likely indicate? → Blocked or restricted condenser
25. What does 'tack cloth' primarily remove before painting? → Surface contaminants and dust
26. The race (cup) of a bearing can be dented after it has been shock loaded. What is the type of this sort of bearing failure? → Brinelling
27. Which of these materials is commonly used for high-performance exhaust systems due to its corrosion resistance? → Stainless steel
28. What is the main advantage of using a variable geometry turbocharger (VGT) on a light vehicle diesel? → Better boost response across a wide RPM range
29. Which component converts the alternator's AC output into DC for the vehicle? → Rectifier diodes
30. What is the proper torque sequence for heavy-duty wheel lug nuts? → Star pattern