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. Two 6-ohm resistors are connected in parallel. What is the total resistance? → 3 ohms
4. A non-zero thrust angle on a solid rear axle vehicle causes: → The vehicle to dog-track and the steering wheel to be off-center
5. During an EVAP system leak-test monitor, how is the canister vent valve normally commanded? → Closed, to seal the system
6. What does a thermostat stuck open typically cause? → Slow warm-up and poor heater output
7. An out-of-round brake drum will most likely cause what? → Pedal pulsation or a grabbing feel during braking
8. 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
9. What is the purpose of the spark plug gap? → To provide the correct arc distance for igniting the air-fuel mixture
10. Why does the lower radiator hose often have a coiled wire spring inside it? → To keep the hose from collapsing under water pump suction
11. During a safety inspection, a tire has a nail in the tread within the repairable area. What is the industry-approved repair method? → Combination patch-plug installed from inside after demounting
12. On a duo-servo drum brake, where is the primary shoe (usually the one with the shorter lining) installed? → Toward the front of the vehicle
13. A vehicle undercharges, but the alternator tests good on the bench. What is a likely cause? → A loose or glazed drive belt
14. An engine coolant temperature sensor is a negative temperature coefficient (NTC) thermistor. As coolant temperature rises, its resistance: → Decreases
15. Thrust angle is the angle between the vehicle's geometric centerline and the: → Direction the rear wheels point
16. When measuring wheel bearing play on a vehicle with a sealed hub unit, which reading generally indicates replacement? → Any noticeable end play beyond manufacturer spec, usually near 0.000 to 0.002 inch
17. The fuel pump primes for 2 seconds at key-on but does not run while cranking, and the engine won't start. What is the most likely cause? → A faulty crankshaft position sensor signal
18. On a parallelogram steering system, which component connects the pitman arm to the idler arm? → Center link
19. At warm cruise, short-term fuel trim reads +5% and long-term fuel trim reads +15%. What do these readings show? → The PCM is adding about 20% fuel to correct a lean condition
20. What happens if the coolant mixture is more than about 70% antifreeze? → Freeze protection and heat transfer both get worse
21. A blower motor operates only on the highest speed setting. What is the most likely cause? → A failed blower motor resistor
22. In a series circuit, what happens to total current when an additional resistor is added? → Current decreases
23. 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
24. A voltage drop test across a ground connection reads 1.2 volts while the circuit operates. This indicates: → Excessive resistance in the ground connection
25. During a cylinder leakage test, air is heard escaping from the oil filler opening. Which component is leaking? → Piston rings
26. Which starter solenoid winding is effectively de-energized once the solenoid's main contacts close? → Pull-in winding
27. A permanent-magnet power window motor changes direction by: → Reversing the polarity applied to the motor
28. 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
29. Before condemning an oil pressure warning light, the technician should first: → Verify actual oil pressure with a mechanical gauge
30. Which spark plug electrode material offers the longest service life in modern vehicles? → Platinum or iridium