Vehicle Inspection and Basic Control
Vehicle Inspection and Basic Control
This domain tests whether you can confirm a commercial motor vehicle is safe before moving it and control it smoothly once you do. Expect questions on inspection order, critical components, and the start-to-stop sequence.
Core rules
- A complete pre-trip inspection covers the vehicle overview, engine compartment, walk-around, lighting, brake tests, and in-cab checks. Look for tire tread and sidewall damage, fluid and air leaks, loose or missing parts, burned-out lamps, and improper coupling.
- Start the engine according to the manufacturer's procedure, then check oil pressure, air pressure, warning lights, and gauges. Adjust mirrors and fasten the seat belt before releasing the parking brake.
- Build air pressure before moving. Accelerate smoothly, steer with both hands, and stop progressively rather than locking wheels. Report defects; do not drive an unsafe vehicle.
Worked example
A driver shuts off the engine, releases the parking brake, and watches the air gauge for one minute. It falls from 100 psi to 97 psi. That 3-psi drop fails the static leak test because the allowable loss is less than 2 psi per minute. The driver should not sign the inspection as satisfactory; the leak must be found and repaired before dispatch.
Traps that cost marks
Skipping the walk-around because the vehicle was inspected yesterday; checking only that lamps illuminate rather than that they are the correct color and function; releasing the parking brake before air pressure is adequate; and ignoring a warning lamp because the engine still runs.