ASVAB Automotive Information Test 5

Question 1

What is the purpose of VANOS or variable valve timing (VVT) systems?

Accepted Answer

Optimize valve opening and closing timing across different RPM ranges

Answer

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.

Question 2

A technician notices a milky, frothy substance on the oil dipstick. What does this most likely indicate?

Accepted Answer

Coolant is mixing with the engine oil

Answer

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.

Question 3

What is the purpose of a vehicle's traction control system (TCS)?

Accepted Answer

Prevent drive wheels from spinning excessively during acceleration

Answer

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.

Question 4

What does a vehicle's knock sensor detect?

Accepted Answer

Abnormal combustion (detonation/pinging) in the cylinders

Answer

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.

Question 5

Which of the following best describes the role of the torque converter's stator?

Accepted Answer

Redirect fluid from the turbine back to the pump to multiply torque

Answer

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.

ASVAB - Armed Services Vocational Aptitude Battery Practice Test

ASVAB - Armed Services Vocational Aptitude Battery Practice Test

ASVAB Automotive Information Test 5