Munich - Defective headlights, broken indicators – for years, problems with car lighting systems have made up the largest category of faults discovered in roadworthiness inspections. Now this continuing trend has been confirmed yet again by the 2014 TÜV Report. Seven per cent of cars presented for their first roadworthiness inspection appear in a 'bad light'. Many lighting faults have now been reclassified as significant faults because of their relevance to safety. But why are drivers so unwilling to take care of their lighting systems? TÜV SÜD's experts analyse the root causes.
"But it's only a blown bulb" is a typical reaction by drivers when inspectors point out faulty lighting during the roadworthiness inspection. "There's a widespread lack of understanding of the problem", reports Eberhard Lang from TÜV SÜD. One reason for the high number of faults is evidently lack of awareness of the important role played in road safety by correctly functioning lights. Another reason can be found in the regulations of the roadworthiness inspection: "Requirements have become considerably more rigorous in recent years, and our scope for latitude has shrunk a good deal", explains Lang. Under these new regulations, faults in car lighting systems have been classified as significant since 2012 – meaning that the car will not pass its roadworthiness test until the faults are repaired.
Reliability: Headlamps and other lights have certainly improved in recent decades. Many bulbs have longer life-spans; xenon headlamp bulbs generally only need to be changed once throughout the entire lifetime of the vehicle. LEDs are now frequently used for signalling lamps like indicators, brake and rear lights, and need no replacement at all. More reliable cabling and improved lamp sockets have also helped to reduce the number of problems. Technically, then, things could hardly be better. However, the 2014 TÜV Report confirms the fact that at an average of 16 per cent, significant faults in lighting systems account for a far higher percentage of major defects than, say, brakes, which weigh in at just over one per cent.