Munich (Pressweb) - 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.
Awareness: Many drivers have failed to grasp that car lights are a safety factor – like brakes or steering, for example. "Few drivers would dream of taking to the road with brakes that only work on one side, but many are happy to overlook a defective headlamp for months on end", notes the TÜV SÜD expert. Even warning lamps on the dashboard are ignored. Although the law was also more generous about classifying lighting defects up to a few years ago, the legal position is now unambiguous: lighting faults must now always be repaired "immediately".
Inspection criteria: Tougher rules were introduced for roadworthiness inspections two years ago. Now even headlamps that are set too low count as a significant fault and will ensure the car fails to pass its roadworthiness test. "In fact, it's only logical to give this problem the same weight as headlamps that are set too high", explains Eberhard Lang. "Inadequate headlamp range can also impact on safety." A further 'significant fault' that is frequently encountered is a non-functioning headlight levelling system – not something that drivers usually spend much time worrying about. "Car owners are often astonished because they have never even noticed the switch, let alone used it", says the expert. However, this ignorance does not exempt drivers from the need to have the fault repaired before their vehicle can get through the inspection.
Parts: Many problems are caused by the use of flawed parts in repairs. "Not all the lamps available on the market comply with the required tolerances", warns Lang. Today's bulbs are high-tech components. Replacing them with parts of dubious quality may mean that headlamp settings or light distribution patterns are no longer correct. The risk of these faults can be at least reduced by using branded lamps. However, after replacing a bulb the headlamp setting should always be checked and adjusted if necessary. This task, and the equipment it requires, must meet high standards; this is no time for do-it-yourself solutions.
Conversions: In the past, incorrectly installed headlamps have frequently given grounds for complaint. Today, problems are more frequently related to the irregular assembly and setting of daytime running lights. When the main headlights are on, these lights must not be operational or must be dimmed. If this is not the case, the roadworthiness inspector must point it out. And inspectors must naturally take action if they discover illegal lighting systems have been installed. "These include 'conversion kits' designed to install xenon lamps or LED modules in halogen headlights", explains Lang. This changes the headlights' optical characteristics, with the result that they dazzle. Parts without official approval are increasingly prevalent and are causing statistics to rise.
Quick check: All driving schools teach it, but hardly any drivers actually do it: every time before setting off, drivers should check that their lighting system is working correctly. But it's a mystery why they do not even bother to do this before heading to the garage for their roadworthiness inspection. "Workshops are often presented with cars where a rear or brake light is not working", notes Lang. "That's something that anyone can spot for themselves and have fixed." Which would save drivers the costs and time of having to bring their car back for re-inspection.
Information: The 2014 TÜV Report is available in German only at TÜV SÜD service centres and from retailers from Friday 6 December 2013 and costs EUR 4.50.
All information about the 2014 TÜV Report can be found at www.tuev-sued.de/tuev-report-2014 (only available in German).