Halogen lamp adjustment, Headlight alignment (Articles)

Interesting facts about adjusting the brightness and tips for setting the light

The following article uses VCDS for diagnostic work, available at the Dieselschrauber VCDS Shop:

1. Different types of light intensity adjustment
1.1. Manual, non-electric light adjustment
Manually adjusting the headlights directly on the headlight using adjustment knobs or screws. This is no longer permitted for vehicles first registered in Germany from 01.01.1990 (e.g., older Golf II models still had this system). This system is occasionally still found in EU-reimported older vehicles (e.g., VW Vento, if ordered from Italy or Austria).

Setup is performed as described below.


1.2. Electric Light Level Regulator (ELLR)
Electric headlight leveling using adjustment knobs in the dashboard. The headlights are correctly adjusted to the zero position of the headlight leveling regulator in the dashboard. After that, it is possible to turn off the headlights using the parking light lever when loading.

Functionality: The LWR (Light-Activated Headlight) system includes a sliding potentiometer and a small control electronics unit (occasionally, this unit is also located in the rotary control). The rotary control itself is also a potentiometer. Therefore, the set inclination value results in a specific resistance of the rotary potentiometer – the electronics adjust the potentiometer until its resistance value matches that of the rotary control.

Automatic or dynamic regulation does NOT occur upon loading changes; manual regulation is always required.

Schematic Overview of Components:
. LWR-Steller with Potentiometer in Headlight
. Wiring to the LWR (Lighting Control Unit) in the dashboard
. LWR-Steller with Potentiometer in Headlight
. Headlight Plus (Power supply when low beam is on) on the LWR switch


Application: Halogen Headlights


1.3. Automatic Headlight Adjustment (ALWR)
The ALWR typically has one, and occasionally two, sensor units on the front and/or rear axles, which determine the suspension angle. This is controlled via a separate headlight control unit, which essentially functions in a similar way to a normal headlight control unit by comparing the values of the axle sensor and the ALWR adjuster in the headlight.

The only difference is that it is automatically regulated. There is only a one-time or, in some vehicles, a constant, but very slow, adjustment of the status changes. A permanent correction of each vehicle movement does NOT occur.

As a retrofit solution, HELLA offers the ALWR, which operates using an ultrasonic sensor on the rear axle. This sensor measures the distance between the rear axle and the ground once, immediately after the light is switched on, compares this value to the stored zero value, and if necessary, adjusts the headlight settings.


Schematic Overview of Components:
. LWR-Steller with Potentiometer in Headlight
. Wiring to the ALWR Control Unit
. Potentiometer sensors on the front and/or rear axle


Application: Vehicles from 01.01.2000 with Xenon headlights or also permissible as a retrofit solution for halogen headlights


NOTE: For vehicles with xenon headlights, the ALWR (Automatic Long-Range Headlights) are mandatory, but not the dynamic ALWR described in section 1.4 below!


1.4. Dynamic Headlight Adjustment (DLWR)
Dynamic headlight adjustment is the most advanced type of headlight adjustment. It works in the same way as the automatic headlight adjustment described in section 1.3, except that instead of the normal headlight adjusters, stepper motors with potentiometers are used. These rules permanently eliminate all road irregularities, such as vibrations caused by acceleration or braking, and thus ensure optimal visibility and optimal prevention of glare.

Recognizable by Xenon headlights, which briefly rise and fall once after being switched on to perform the zero-position calibration.

Also, in combination with accent lighting!


Schematic Overview of Components:
. LWR Step Motors with Potentiometer in Headlight
. Wiring to the DLWR Control Unit
. Potentiometer sensors on the front and rear axles


Application: Vehicles from 01.01.2000 with Xenon headlights


2. Adjusting the headlights


2.1. Setting with LWR

. Vehicle is fully fueled.
. Vehicle is fully spring-loaded at the front and rear.
. Vehicle is parked.
. LWR-Controller set to "0" (Recommended for avoiding inaccuracies: Briefly set the dimmer to the highest value and then back to "0", then use the spotlights to cover the entire area)


Now adjust the headlights with the adjustment tool so that an image like in Scheinwerfereinstellung.png is achieved.

Each headlight has 2 adjustment screws, one for height and one for adjusting the lens position.


It is recommended to first adjust the page adjustment so that the point of convergence of the light beam lies exactly above, perpendicular to, or below the marked point on the adjustment line of the spotlight adjustment tool.

Then adjust the headlights so that the line along the edge of the light aligns.


Important: Maintain a distance of approximately 30-75cm from the vehicle. Position the adjustment device parallel to the vehicle and pay attention to the inclination angle (1.0% / 1.2%) printed on the headlight and adjust the device accordingly.


2.2. ALWR and DLWR settings


. Vehicle is fully fueled.
. Vehicle is fully spring-loaded at the front and rear.
. Vehicle is parked.
. Using diagnostic software VCDS to set the LWR control unit to the basic settings mode ("learn default position") e.g. adjusting Xenon headlights with VAG-COM / VCDS

Example Golf IV in the specified position:

Quote:

Select with VCDS STG 55 (Headlight Adjustment) STG Measurement Groups -> Function 08 Measurement Group 000 Go to Default Settings

After that, the headlights will be adjusted as with a normal LWR.



2.3. Setting when no adjustment device is available

A principle approach is also possible if you have a white wall and a flat surface in front of it.

It is recommended to park the vehicle 10 meters away from the wall at a 90-degree angle. All other conditions (full tank, properly sprung, etc.) must also be met.


After these measurements are taken:

. Height between the ground and the lamp socket / center of the glass lens in reflector spotlights.
. Inclination factor on the headlight (e.g., 1% or 1.2%)


First, it is advisable to adjust the desired left-right aiming of the headlights. For this, mark a 90-degree angle between the light source and the wall, as shown in LWR1.png.

Here, you can obtain the "black center" in the above image of the headlight adjustment tool. Perform this for both headlights.

Now, the required height needs to be calculated, for example:

. Vehicle with a 1% slope (i.e., 1 cm per 100 cm of distance)
. Headlight center height on vehicle 100cm

=> at a distance of 10m, a height of: 100cm - (10 * 1cm) = 90cm should be marked.


To simply mark a horizontal line (using tape) on the wall at a height of 90cm (or the calculated height), move the previously marked center point vertically onto the line, and then adjust the headlights as usual.


Of course, it's also possible with 1m, 3m or 5m wall distance, you just have to convert accordingly. The further you go, the more accurate it becomes, but 1m is not sensible because of the 1cm.