Headlights are now so sophisticated that you need new technical skills to replace them correctly. Neil Riley, product manager for Hella who make many OEM headlight units, explains both the technical talking points and the repair solutions.

ED lights are replacing Xenon and Halogen headlight at a much faster rate than anyone could have predicted. Such is the market penetration of LED that the technology of the actual headlamp units and production methods means that they are more affordable than ever. Technology such as LED lighting that was reserved for prestige models can now be found on the ‘eyes’ of more humble cars such as Corolla’s, Mazda and Hyundais. Meanwhile HELLA continues to develop its Matrix LED systems and has recently launched the next generation of lighting technology. With the so-called "Solid State Lighting | High Definition" (SSL | HD) technology, the company has further miniaturised the light source so that 15,000 LED pixels can now be individually and intelligently controlled. This should be available on the road in the next three years.
Individualisation is a growing trend in the entire automotive industry. Against this background, HELLA is working on new lighting solutions that can be integrated into the vehicle architecture in a much smaller space while maintaining high performance and functionality, offering original equipment manufacturers additional degrees of freedom in individual vehicle design. This is achieved, for example, through miniaturisation concepts. With the SSL | HD technology, HELLA has now integrated very small, individually switchable LED pixels on intelligent driver chips. By controlling the individual pixels, the light distribution on the road can be generated directly at the light source surface and projected onto the road via a multi-stage optical system. The higher number of pixels and the enlarged light-emitting surface allow new applications with higher light quality and performance.
At the top level of current headlamp technology is the fully adaptive high beam unit. This allows you to drive on high beam all of the time while a camera in the windscreen adjusts the light for oncoming vehicles, those in front and to avoid even the dazzle of road signs. This technology will also filter down into the ‘mum and dad’ car pool.
The integrated nature of headlights and ADAS systems in general is an issue for technicians the world over who need to adapt to properly understand how to use diagnostic tools in the repair process rather than just use them for pre and post scans. It’s all very well to have the OE repair methods for a headlight replacement but you have to understand what they mean and how to implement them.
The old days of taking a headlight out fo the box, fitting it and using a levelling unit are gone. You need a diagnostic unit to tell you how to carry out the headlamp alignment, which might be mechanical or it might be that only the diagnostic unit can tell the headlamp where to aim. Even for less sophisticated modern headlamps you need both a beam setter and a diagnostic unit. And the beam setter has to cater for both horizontal and vertical line setting rather than just the old asymmetric setting. As well as ensuring that the vehicle is the correct distance away there can be a number of other conditions, which vary from model to model, that need to observed in order to properly ensure that the headlight will function as designed by the OEM. This includes tyre pressure, specific workshop floor conditions, the fuel level, and some demand 75 kilos to be present in the driver’s seat.

This article was first publised in Paint & Panel 

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