ASVAB Automotive Information Practice Test 859111

Questions 5
Topics Actuators, Battery, Ignition Timing, Sensors, Transmission

Study Guide

Actuators

Actuators receive signals from the powertrain control module and carry out adjustments needed based on the data the PCM received from the sensors.

Battery

The lead-acid battery is the core of the electrical system, providing current to the ignition system to start the engine as well as delivering supplemental current when the alternator can't handle high electrical system loads and acting as an electrical reservoir for excessive current.

Ignition Timing

Ignition timing defines the point in time at the end of the compression stroke that the spark plug fires. Measured in number of degrees before top dead center (BTDC), the exact point that the spark plugs initiate combustion varies depending on the speed of the engine. The timing is advanced (the spark plugs fire a few more degrees BTDC) when the engine is running faster and retarded when it's running slower.

Sensors

Sensors provide the data necessary for the vehicle's computer to make decisions and monitor everything from simple vehicle information like tire pressure to complexities like the chemical content of an engine's exhaust.

Transmission

The transmission provides the appropriate power to vehicle wheels to maintain a given speed. The engine and the transmission have to be disconnected to shift gears and a manual transmission requires the driver to manually manage this disconnection (using a clutch) and to manually shift gears. An automatic transmission is essentially an automatic gear shifter and handles this process without driver input.