Info: Retrofit headlight range adjustment in the vehicle!

Recently updated on September 20, 2021 at 09:53 am

You are looking for useful tips on the subject Luminous range control of vehicles? What is the system doing? Can it be retrofitted? When does retrofitting even make sense? Then you are right here. There are two main factors that affect the range of the headlight, apart from the brightness itself. That's the Loading condition and the Nodding movement of the vehicle. Both can adjust the headlight range change. A changed headlight range can lead to glare other road users. In order to avoid this, the legislator has a headlight range control through special systems (LWR) required by law. The systems are therefore important for safe driving and compliance with legal regulations. Accordingly, you should of course also know the most important information about the systems. In this article you will learn how the systems mostly work and how their Functionality can checkwhat to do in the event of a malfunction and how headlights with automatic headlamp leveling can be set.

Legal requirement

LWR systems are mandatory for new vehicles. The regulations can be found in directives 76/756 / EEC and ECE-R48 and have existed since 1993.

automatically or manually

As already mentioned at the beginning, the task of the headlight range control is the so-called Light-dark border always to the Loading condition of your own vehicle. In order to prevent oncoming traffic from being dazzled, such systems are not only mandatory, they are also installed in all current vehicles. It is between manual systems and automatic headlight range adjustment  distinguished.

The name suggests it, of course. With manual systems, the driver has to use a switch even set the headlight inclination, which regulates the headlight range. The manual systems can do this pneumatic as well as work electrically. The systems usually work as they should. The problem, however, is that motorists are often not sufficiently informed about the systems and so are glare occurs anyway.

Retrofitting LWR possible?

Is your own vehicle, for example not Equipped with a xenon headlight, but if a retrofit is to take place, an automatic headlight range control is mandatory. A special kit for retrofitting is therefore usually required with automatic headlight range adjustment. Will the retrofit with OEM components carried out, the automatic headlight range control must be purchased and installed separately.

Vehicles with halogen headlights and without standard headlight range adjustment can of course also have a corresponding system. There are many providers on the market for this. If hydraulic adjustment is already installed ex works, even the headlights can normally be used can be reused. Then only the Motors from the retrofit kit installed instead of the hydraulic adjuster. Got the old headlights no hydraulic headlight range adjustment and also no attachment for the adjuster then new headlights are needed. Tip: You can find more information on the topic here Retrofit xenon headlights.

The technology takes over - automatic headlight range control

Basics of the automatic LWR: The big difference and also advantage of automatic LWR systems is that this is the case without activity of the driver's work. There are two different systems here. The quasi-static and the dynamic LWRs.

What is a quasi-static headlight range control?

The quasi-static LWR regulates or corrects a change in incline based on the load status of the car. There are sensors on the front and rear axles, which are compared in a control unit with the target data of the vehicle and, if there are deviations, trigger the servomotors of the headlights accordingly. The servomotors often resemble those of a manual LWR. If it is a compact vehicle without a long wheelbase, the system can do without the front axle sensor. The inclination change occurs here often only on the rear axle on. A quasi-static system only intervenes in the event of prolonged body inclinations, as it comes along with great damping. You should be one Xenon conversion set from a well-known manufacturer, then there is an ultrasound-based system that measures the distance to the road using a sensor. One provider is, for example, HELLA.

Variant two - dynamic LWR

In contrast to quasi-static LWR systems, dynamic systems react changes in inclination due to driving. For vehicles with Xenon headlights dynamic LWR systems are standard today. The driving-related inclination changes that cause the systems to react are, for example Accelerate or Brakes. The dynamic systems also have a control unit that compares the sensor data with the target data, taking into account the current driving condition. The big difference besides the factor for the calculation is that Reaction speed of dynamic systems. These adjust the servomotors of the headlights in a fraction of a second, so quasi-static systems react so quickly not. So that this response time is possible, dynamic LWR systems mainly use Stepper Motors used as actuators on the headlights.

The right headlight range adjusters for both types of system - manual and automatic

The current market clearly shows that electric headlight range adjusters are the way-to-go. These are now in the 3rd generation (version 3i) and come up with many optimizations compared to their predecessors. The manufacturer HELLA is primarily known for very customer-specific solutions for LWR systems. The range extends from LW actuators for installation in the headlamp or for outdoor mounting and this mit oder ohne manual basic setting. Then there is still 12 V and 24 V versions.

Practical tips for dealing with errors in an LWR system

If there is an error while driving, the driver will be informed about a Signal light or by one Note text informed about the occurrence of the error in the cockpit. Depending on the system, the headlights will now remain in their current position or in their original position Starting position brought back.

What can be damaged in LWR systems

• defective servomotors on the headlights
• Headlights are not adjusted (basic setting)
• defective control unit
• defective data line
• defective LWR sensor for the vehicle level
• Control unit has been renewed but not coded
• No supply voltage
• mechanical damage present

Check function of the LRW system

With automatic LWR systems there is usually a Diagnostic tester necessary, you should want to adjust the headlights. This is of course also used to diagnose the State of the system possible. A check can also be carried out with a multimeter and oscilloscope. Either way, you should have a circuit diagram of the system.

How to check the system

• Vehicle unloaded place on a flat surface
• Align the SEG in front of the vehicle
• Switch on low beam
• Check the correct cut-off line
• Load the rear (loading the trunk), quasi-static headlamp leveling controls the headlights after a few seconds (can be followed on the SEG), dynamic headlamp leveling controls in a very short time (control process can often only be perceived as a brief "twitch" on the test screen of the SEG)
• In some vehicles, the control only works when the vehicle is in motion

Measurements in the absence of a control process

• Check the supply voltage on the servomotors, control unit, LWR sensor
• Check LWR sensor, data cable for mechanical damage
• check correct installation position
• check the sensor signal using an oscilloscope
• Check parameters and actual values ​​using the diagnostic tester

Tip: 25 watt xenon variant without SRA

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