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. What component in an automatic transmission controls the timing and quality of shifts in a modern electronically controlled unit? → Valve body solenoids controlled by the TCM
2. During a clutch replacement, a technician finds the flywheel surface has heat cracks and hard spots. What is the recommended repair? → Resurface the flywheel if within specifications or replace it
3. A 4WD vehicle with a transfer case makes a grinding noise only when in 4WD high or low but operates quietly in 2WD. What is the MOST likely cause? → Worn or damaged transfer case chain or planetary gears
4. What is the purpose of the spark plug gap? → To provide the correct arc distance for igniting the air-fuel mixture
5. A front-wheel-drive vehicle equipped with a transaxle has a clicking noise that occurs only when turning. What is the MOST likely cause? → Worn outer CV joint
6. After replacing an automatic transmission, the technician finds the vehicle has a 2-3 shift flare. What was MOST likely overlooked during the rebuild? → The 2-3 clutch pack clearance was set too wide
7. Which spark plug electrode material offers the longest service life in modern vehicles? → Platinum or iridium
8. What typically causes carbon tracking on a spark plug boot or ignition coil tower? → Compromised insulation allowing voltage to arc along the surface to ground
9. Which component of the braking system generates friction to stop the vehicle? → Brake pads
10. A FWD vehicle makes a loud clunking noise during acceleration from a stop but not at steady speed. What drivetrain component is MOST likely at fault? → Worn or loose inner CV joint
11. What is the typical recommended replacement interval for iridium spark plugs? → 60,000–100,000 miles
12. A manual transmission pops out of 3rd gear under load. What is the MOST likely cause? → Worn or damaged 3rd gear synchronizer hub or detent mechanism
13. When pressure testing an automatic transmission, the technician finds that line pressure is low in all ranges. What is the MOST likely cause? → Both A and B
14. What component is responsible for allowing controlled vertical movement of the wheels over bumps? → Control arms
15. How does a brake booster assist in braking? → Amplifies braking force with vacuum assistance.
16. What diagnostic procedure is fundamental to heating and cooling? → Systematic diagnostic process using scan tools, visual inspection, and test procedures
17. What safety precaution is critical when performing emissions control work? → Following all manufacturer safety warnings, using proper PPE, and securing the vehicle
18. What is the primary function of a vehicle’s shock absorbers? → Dampen spring oscillations for a smoother ride.
19. A rear-axle differential makes a howling noise that changes pitch with vehicle speed but not with engine speed. What is the MOST likely cause? → Improper ring and pinion gear backlash or worn gear teeth
20. In a distributor-less ignition (DIS) system, what does the camshaft position sensor determine? → Which cylinder is on its compression stroke to fire the correct coil
21. How does the power window system in a modern vehicle function? → Operates through an electric motor and regulator.
22. When setting up a ring and pinion gear set in a rear axle, what does the gear tooth contact pattern indicate? → The correct pinion depth and backlash adjustment
23. What can cause a vehicle to pull to one side while driving? → Improper wheel alignment or uneven tire pressure.
24. Which symptom indicates worn-out brake pads? → Squeaking or squealing noises
25. What diagnostic procedure is fundamental to fuel systems? → Systematic diagnostic process using scan tools, visual inspection, and test procedures
26. What is the MOST common cause of automatic transmission overheating in a vehicle used for towing? → Insufficient cooler capacity for the added load
27. Which type of distributor trigger sensor produces a clean digital square wave signal? → Hall-effect switch sensor
28. What is the primary function of the ignition control module (ICM)? → Switch primary coil current on and off to induce secondary high voltage
29. How should a technician verify a safety inspections repair is complete? → Perform a thorough road test, recheck all work, and verify with diagnostic tools
30. How should a technician verify a emissions control repair is complete? → Perform a thorough road test, recheck all work, and verify with diagnostic tools