Vehicle Safety and Maintenance
This domain tests the checks a driver is expected to make and the meaning of warning lights - the faults that cause real roadside breakdowns and roadworthiness failures.
Regular checks
- Tyres: legal minimum tread is 1.6 mm across the central three-quarters of the breadth and around the whole circumference. Check pressures when cold, against the handbook figure, and include the spare.
- Lights: headlights, brake lights, indicators, hazard lights and the number plate lamp.
- Fluids: engine oil on level ground with the engine cold, coolant only when cold, brake fluid, screen wash.
- Visibility: wipers, washers, clean glass, correctly adjusted mirrors, clear windscreen.
- Load: secure it; it must not obstruct lights, plates or your view, and must stay within permitted weights.
Warning lights
- Red oil pressure or red coolant temperature - stop safely and switch off; continuing can destroy the engine.
- Red brake warning - check the handbrake first, then treat it as a fault.
- Amber engine, ABS or ESC light - the system may be disabled; drive cautiously and get it checked.
- Tyre pressure warning - check pressures at the first safe opportunity.
Worked example
A front tyre measures 1.4 mm at the centre and 3 mm at the shoulders. The centre is the part that grips and clears water, and 1.4 mm is below the 1.6 mm minimum, so the tyre is illegal regardless of the shoulders. Fit a replacement of the correct size and load rating: the vehicle would fail its roadworthiness test and the driver risks a fine.
Traps
Checking pressures after a fast run, when hot tyres read high; thinking tread is measured only in the centre groove; ignoring an amber light "because the car drives fine"; topping up coolant with the engine hot.