Vehicle Technical Knowledge and Maintenance
What the exam expects you to know
You should understand the function of the main systems and the checks a driver can perform. Tyres: tread depth must be at least 1.6 mm across the central three-quarters of the tread and around the whole circumference, and pressure should be checked cold. Under-inflation raises fuel consumption, heats the tyre and increases blow-out risk. Brakes: a spongy pedal or a pull to one side signals a fault; brake fluid absorbs moisture and needs periodic replacement. Lights: all lamps must work, be correctly aimed, and be clean. Steering: excessive play or vibration indicates a problem.
Fluids and the engine bay
Engine oil, coolant, brake fluid, and windscreen washer fluid are the four checks a driver should be able to do. Check oil with the engine off and level ground. Never open the coolant cap when the engine is hot. The battery should be secure and terminals clean; modern vehicles warn of low charge.
Warning lights
Red warning lights mean stop and investigate: oil pressure, coolant temperature, brake system, battery charging. Amber lights mean caution or a system fault: engine management, ABS, tyre pressure. A red oil-can light means stop the engine as soon as it is safe, because continuing can destroy it.
Worked example
A tyre-pressure warning appears. The correct answer is to check pressures at the next safe opportunity, not to ignore it or to rely on the system to correct itself. If a tyre is visibly deflated, stop and change it or call assistance rather than driving on it.
Traps to watch
Questions often confuse the minimum tread depth with a recommended depth, or ask whether tyre pressure is checked hot or cold. Cold is correct. Also remember that ABS does not replace adequate tyre tread or a safe following distance.