Automotive Information Test Flashcards
7 cards from real ASVAB practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Automotive Information Test flashcards as text
What is the purpose of VANOS or variable valve timing (VVT) systems?
Answer: Optimize valve opening and closing timing across different RPM ranges
Variable valve timing systems adjust when intake and/or exhaust valves open and close based on engine speed and load, improving power, efficiency, and emissions across the RPM range.
A technician notices a milky, frothy substance on the oil dipstick. What does this most likely indicate?
Answer: Coolant is mixing with the engine oil
A milky or frothy appearance on the dipstick indicates coolant contamination of the engine oil, typically caused by a blown head gasket or cracked engine block.
What is the purpose of a vehicle's traction control system (TCS)?
Answer: Prevent drive wheels from spinning excessively during acceleration
Traction control detects when a drive wheel spins faster than the others during acceleration and reduces engine power or applies the brake to that wheel to restore grip.
What does a vehicle's knock sensor detect?
Answer: Abnormal combustion (detonation/pinging) in the cylinders
The knock sensor detects the vibration frequencies produced by engine knock (pre-ignition/detonation) and signals the ECU to retard ignition timing to prevent engine damage.
Which of the following best describes the role of the torque converter's stator?
Answer: Redirect fluid from the turbine back to the pump to multiply torque
The stator sits between the pump and turbine and redirects returning fluid in a direction that assists the pump rotation, multiplying torque output at low vehicle speeds.
When replacing brake pads, why is it necessary to compress the caliper piston back into its bore?
Answer: To create clearance for the thicker new brake pads to fit over the rotor
As brake pads wear, the caliper piston extends outward; new pads are thicker, so the piston must be pushed back in to allow the caliper assembly to fit over the rotor.
What is the primary function of an engine's harmonic balancer (crankshaft damper)?
Answer: Reduce torsional vibrations in the crankshaft
The harmonic balancer absorbs and dampens the torsional (twisting) vibrations created by combustion pulses acting on the crankshaft, preventing fatigue cracks and bearing wear.