Buick Regal: Headlamp Aiming

General

Directive 76/756 EEC and ECE-Regulation 48 cover checking and aiming of headlamps on vehicle.

Correct aiming of headlamps of vehicles should enable optimal road illumination by the low beam, with minimal glare to oncoming traffic. For this purpose the inclination of the light beam in relation to the road surface and the angle of the beam to the vertical longitudinal plane running through the vehicle centre must comply with the requirements laid down in the ECE regulation and EEC directive.

Glaring of the low beam is considered eliminated if the intensity of the illumination at a distance of 25 m (82 ft) from each individual headlamp on the plane perpendicular to the road and at the height of the headlamp as well as above, is not greater than 1 lux. This requirement is generally satisfied if the headlamp aiming is carried out according to these aiming guidelines.

For the nondazzling high beam (Intelilux) special attention must be turned to the correct lateral alignment of the headlamps (low beam).

If a non-railed adjustment device will be used, the lateral orientation of the adjustment device has to be checked separately in front of each single headlamp.

The measurement of adjustment for the basic headlamp aiming is displayed in % on the headlamp housing.

Example: Label for a headlamp inclination of 1.0% for the low beam on the headlamp.

Reference 1.0 percent corresponds to the adjustment dimension of the headlamp with reference to the inclination of the light beam. The inclination at a distance of 10 m (33 ft) from vehicle headlamp is therefore 10 cm (4 in). The inclination of the low beam headlamp is indicated by its light/dark boundary (cut-off line).

Depending on the specific inner design of the headlamps, the movement of the lightbeam on the measurement screen is not exactly vertical or horizontal during the aiming on the aiming screws. This is caused by the technical solution of the suspension of the reflectors in the headlamp housing. After aiming of one axis the aiming of the other axis should be rechecked. For instance the vertical aiming could be changed a bit after the aiming of the horizontal axis. Therefore the vertical axis must be checked and if necessary aimed again after the aiming of the horizontal axis.

If a headlamp shows a significant deviation from the correct aiming for both horizontal and vertical direction the aiming operation must be performed step by step for the two directions. This means that in such a case the aiming of horizontal and vertical direction must be done alternately in small steps. Not more than one turn of an aiming screw shall be performed at once. After one turn change to the other aiming screw. Repeat this procedure until the headlamp is correctly aimed.

Headlamp Beam Setter / Inspection Station

Abbreviations used:

1. Horizontal distance between headlamp centres
2. Central marking
3. Test surface

3. Test surface
4. Road surface
5. Break point (kink of cut-off line)

e = Aiming dimension in cm, e = H - h (aiming dimension, low beam headlamps usually at 1.0 percent,

e = 10 cm (4 in), front fog lamps 2.0 percent, e = 20 cm (8 in), high beam headlamps (if separately amiable) at 0 percent, e = 0 cm (0 in).

H = Height of centre of headlamp over road surface

h = Height of light/dark boundary line (cut-off line) of low beam above road surface

The headlamp aiming is performed according to the specifications, as shown in the illustrations, using an adjuster. When using a headlamp adjuster, set up the height and position of the adjuster according to the instructions in the operation manual. Ensure that the vehicle tire surface that is in contact with the road and the surface for setting up the adjuster are at the same level and parallel with each another.

X = Center of adjuster lens (see arrow mark on adjuster housing) must be aligned on the same level as the low beam headlamp and must be parallel to the ground.

1 = Use marking of the control mirror (1) to align the adjuster system in the correct angle to the vehicle, based on the information shown in the owner operating instructions.

The distance between the adjuster lens and the headlamp must be max. 0, 9 meters (refer to operation instructions of the adjuster system) The surface on which the measuring instrument (adjuster system) and the vehicle stand must be flat. See following table.

Vehicle tires must have specified air pressure. Blackened bulbs must be replaced before adjusting.

The adjustment is performed at vehicle curb weight plus one person or 75 kg (165 lb) on the driver's seat. (Curb weight = weight of vehicle ready for use with 90% filled fuel tank plus the weight of all equipment carried during use, e.g. spare wheel, tools, jack, first aid kit, emergency warning triangle, etc.).

Light Pattern / Scheme of Headlamps

1. Kink of cut-off line for the left/right setting
2. Horizontal area of the cut-off line for up/down setting

1 and 2 = Depending on the headlamp setup the outer sections will be straight or increasing.

Headlamp Aiming

The headlamp switch must be turned on manual low beam if equipped, the manual headlamp range adjustment has to be in the zero position.

Halogen Headlamp

1. Aiming screw for vertical adjustment
2. Aiming screw for horizontal adjustment

LED-Matrix Headlamp

1. Aiming screw for vertical adjustment
2. Aiming screw for horizontal adjustment

NOTE: Guide and adjust the headlamps always from below to the horizontal area of the separation line

For the vertical adjustment (adjustment of the height), the separation line has to be on the left side of the adjustment cross parallel to the horizontal adjustment line (1).

NOTE: At first perform the vertical (1) and then the lateral adjustment. Check the vertical adjustment again after the lateral adjustment.

To assure the correct lateral adjustment the horizontal increase (inflection point) must lay on the vertical separation line A (0 degree).

This is elementary for a flawless LED Matrix functionality.

NOTE: This description is valid for right hand traffic. For left hand traffic the light pattern of left and right side is mirrored.

The reference run must be performed for the headlamps after headlamp aiming. The reference run result automatic when ignition is on and the headlamp switch be turned on manual low beam. During the reference run check for enough clearance between the projection-type module and the reflector and that the module bezel is free from scratches. In case of a touch condition between the projection-type module and bezel during the reference run or visible scratches on the bezel the headlamp aiming must be checked again. Conditions like these occur if the aiming differs extremely from the set position.

FRONT SUSPENSION AUTOMATIC FORWARD LIGHTING POSITION SENSOR REPLACEMENT

Preliminary Procedure

Tire and Wheel Removal and Installation.

1. Retainer
2. Front Suspension Automatic Forward Lighting Position Sensor Nut
   CAUTION: Fastener Caution
   Tighten 9 N.m (80 lb in)
3. Front Suspension Automatic Forward Lighting Position Sensor
   Procedure
   1. Disconnect the electrical connector.
   2. Unlock the retaining tabs.
   3. Run all necessary programming and setup procedures.

REAR SUSPENSION AUTOMATIC FORWARD LIGHTING LEVELING POSITION SENSOR REPLACEMENT

Preliminary Procedure

Tire and Wheel Removal and Installation.

1. Rear Suspension Automatic Forward Lighting Leveling Position Sensor Nut
   CAUTION: Fastener Caution
   Tighten 9 N.m (80 lb in)
2. Rear Suspension Automatic Forward Lighting Leveling Position Sensor
   Procedure
   1. Disconnect the electrical connector.
   2. Unlock the retaining tabs.
   3. Run all necessary programming and setup procedures.

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