SSL | HD Matrix LED lamps: Interesting facts, repair instructions and practical tips

Here you will find valuable and useful workshop tips on the design, function and diagnostics of the SSL | HD Matrix LED lamps.

Light on the road is going digital. This means that, in future, light distributions will be brought about primarily by means of digital control of high-resolution light modules. As a result, new and diverse application possibilities come into play, one of which would be, for example, the ramping up of road safety. The Solid State Lighting-High Definition (SSL | HD) Matrix module with Liquid Crystal HD technology enables fully adaptive light distribution to suit the relevant traffic situation. The new LCD lamp projects light onto the road with more than 32,000 pixels. This allows the light pattern to be adapted intelligently, continuously and in real time to various driving situations. The following information is presented using a Porsche HD Matrix LED main lamp as an example.

In this LED lamp, four light modules with almost square lenses are arranged on a lamp holder. Two HD modules for the low beam and high beam light functions are mounted in the lower section. Each of these HD modules contains an identical LED array with 16,384 micro-light-emitting diodes, an array which generates a high-resolution luminous flux on a surface area of just 12.8 x 3.2 millimetres. The brightness of the LED array can be adjusted in more than 1000 steps or levels via the system control. And each HD module is equipped with a specially adapted lens having specifically ground optical glass, which creates different illumination angles.

The outer module with wide-angle lens covers an angle of 40 degrees in width and 10 degrees in height. The inner module, on the other hand, is equipped with a telephoto lens and covers an angle of 20 degrees in width and 5 degrees in height. Although the illumination range is only half that of the outer module, it is nevertheless much brighter. As a result of the overlapping of the light distribution of both HD modules, wide illumination with high intensity is achieved in the central area.

With over 32,000 individually controllable pixels per lamp, the HD modules generate high-resolution light that is projected only where it is needed thanks to this kind of light distribution. The pixels in each individual lamp are controlled by their own electronic control unit, which HELLA, as a system supplier, has also developed. Against this backdrop, so-called GMSL (Gigabit Multimedia Serial Link) interfaces are being used for the first time because of the high data volumes involved.

In addition to the basic light functions such as low beam or high beam, extra functions can also be displayed in order to assist the driver

Welcome and goodbye

The LED lighting in the lamps provides additional visibility and safety when the vehicle is opened and closed. When the vehicle is opened, a brand-specific animation is generated by the HD modules and projected onto surfaces opposite. After the ignition is switched off and the driver leaves the vehicle, the animation takes place in reverse sequence

High beam with auxiliary high beam

The auxiliary high beam is activated if the system does not recognise any vehicles in front or any oncoming vehicles when the automatic high beam is switched on. In this case, the two function modules are added to the two HD modules that have already switched from low beam to high beam. This increases the amount of light from 1,400 to 2,500 lumens and the road can be illuminated over a distance of up to 600 metres. The auxiliary high beam is switched off automatically as soon as vehicles in front or oncoming vehicles are detected.

Glare-free high beam with auxiliary function

The auxiliary high beam is deactivated as soon as a vehicle in front or an oncoming vehicle is detected by the vehicle camera. At the same time, the illumination area around the other vehicle is blanked out by the switching off of the relevant pixels. The light energy released as a result is converted into additional functional HD light so that the amount of light on both sides of the gap is doubled, and this ultimately leads to a visible brightening of the remaining high beam area. In this way all of the available HD light continues to be fully utilised in order to optimise the illumination of the road and thus improve visibility for the driver.

Lane assistant for lane narrowings

This function visually projects the width of the vehicle, including the wing mirrors, onto the road for the driver, for example on a roadworks site. This allows the driver to assess whether overtaking would be possible in such a situation. Road safety is consequently improved as both speed and also any correction to steering are then minimised.

Lane brightening

This function is only activated on motorways or comparable roads and serves to improve the illumination of the driver’s own lane. Regardless of the vehicle position, the carriageway between the lane markings is considerably brightened up in the form of an illuminated carpet. The illumination is extended to both lanes as soon as a lane change is being carried out and the lane marking is crossed. Once the lane change is complete, the illumination is adjusted and set to the current lane on which the vehicle is travelling. This allows the driver to recognise objects and hazards at an early stage and to react to a lane change carried out without due care and attention.

Adaptive motorway high beam

In this function, the system control ensures the best possible illumination of the road on motorways or dual carriageways and at the same time adapts the light distribution individually to suit the particular conditions prevailing. At the same time, illumination towards the centre of the road is displayed as a soft transition so as to avoid unnecessary dazzling of oncoming traffic.

A functional failure of the LED lamps can lead to the following effects:

• Fault lamp lights up (system-dependent)
• Fault entry in the relevant lamp or system control unit

The following causes can then be considered:

• Faulty power supply
• External damage or mechanical defects
• Communication and bus systems faulty
• Failure of lamp electronics
• Defective control unit
• Defective fan motor in lamp

After the following types of repair work, the SSL | HD lamp has to be readjusted.

Before the lamps are adjusted, the following vehicle requirements first have to be met:

• The vehicle and lamp adjustment device stand on a level surface
• The parking brake is released and the vehicle is secured against rolling away
• Tyre pressure is OK
• The lamp cover lenses are clean and damage-free
• The steering wheel is in the "straight-ahead" position
• The correct vehicle level is guaranteed. Vehicles that were previously raised must be lowered to the normal suspension level.
• The vehicle load has been checked and, if necessary, adjusted to the load specified by the manufacturer
• The battery voltage is greater than 11.0 volts
• There are no error entries in the system-relevant comfort control units.

In order to adjust the lamps, a diagnostic device is also required as well as a lamp adjustment device. The diagnostic device is used to begin headlamp adjustment, work which is performed by following the specified procedures. If the vehicle is equipped with levelling control, the suspension must be set to normal level and the control deactivated before adjustment is carried out. After a successful setting, the control function is reactivated.