ASVAB Automotive Information Practice Test 527843

Questions 5
Topics Engine Block, Intake Stroke, Powertrain Control Module, Sensors, Transmission

Study Guide

Engine Block

The engine (or cylinder) block is the large casing that contains the cylinders and many of the internal components of the engine.

Intake Stroke

The four-stroke piston cycle of internal combustion engines starts with the piston at top of the cylinder head (top dead center or TDC) during the intake stroke. The piston moves downward in the cylinder creating a vacuum that pulls an air-fuel mix into the combustion chamber through the now open intake valve.

Powertrain Control Module

The main computer or powertrain control module (PCM) uses pre-programmed software to analyze the input received from sensors and produce output signals to adjust vehicle performance and operation. (Engine control unit (ECU) is another name for the PCM.)

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.