ASVAB Automotive Information Practice Questions

A: As the “brain” of the car, it is the job of the PCM to gather signals from the car’s sensors and generate outputs to control the vehicle’s functions. The diagnostic data link, choice (B), connects a scan tool to the PCM; the scan tool, (D), is what technicians use to read the PCM.

C: Proper lubrication of internal moving parts is essential to long engine life. Excessive wear on internal engine parts can occur when the engine oil becomes dirty or experiences degradation of its lubricating properties. Internal combustion engines are lubricated by circulating oil internally, not by lubricating fittings, (A). Changing automatic transmission fluid, (B), does not need to be done frequently and is important to the life of the transmission more than the engine. Thermostats, (D), generally don’t require maintenance; if they fail to function properly they are usually replaced.

B: The combustion chamber, indicated in the diagram by the number 2, is where the actual combustion of the air-fuel mixture takes place. It is located in the cylinder head directly above the piston (1 in the diagram).

B: Coil-on-plug ignition systems eliminate the need for spark plug wires because the ignition coil is mounted directly over the spark plugs. Answer choices (A), (C), and (D) are still necessary components in a coil-on-plug ignition system, and therefore are not correct.

A: A 12:1 ratio of air to fuel would be a rich mixture, fastburning and possibly producing black smoke.