The inspection of a vehicle's external lighting system should cover three aspects: appearance, function, and circuitry. First, all lamp covers must be checked for integrity, ensuring no cracks, stains, or yellowing due to oxidation, to maintain good light transmittance. Functional testing should be conducted in low-light conditions: low-beam headlights should illuminate a distance of 10 meters with a horizontal cut-off line, and their height should be adjusted to 0.6–0.8 times the headlight height to avoid glare; high-beam headlights must be verified for illumination range and brightness; turn signals should flash consistently at 60–120 times per minute; brake lights must activate within 0.2 seconds of pedal depression and be at least 5 times brighter than tail lights. For automatic lighting systems, test whether the photosensor switches modes based on ambient light levels. Circuit checks should include verifying fuse integrity and inspecting plugs for oxidation or looseness; for LED lamps, ensure the flicker rate remains below 300Hz. Particular attention should be paid to side marker visibility, which must be clearly discernible from 30 meters, and fog lights must emit amber or yellow light capable of penetrating rain and fog. Regular professional photometric testing (≥40 cd daytime, ≥80 cd nighttime) ensures compliance with JPJ safety standards. Additionally, clean lamp interiors every 6 months to prevent condensation from impairing optical performance.
