2003 Buick Century Owner's Manual - Page 266

Headlamp Aiming Your vehicle has a headlamp system equipped with horizontal and vertical aim indicators. The aim has been pre-set at the factory and should need no further adjustment. This is true even though your vertical and horizontal aim indicators may not fall exactly on the " 0 (zero) marks on their scales. To check the aim, the vehicle should be properly prepared as follows: The headlamps must be off for one hour prior to aiming and must remain off during this procedure. The vehicle must have all four tires on a perfectly level surface. If your vehicle is damaged in an accident, the headlamp aim may be affected. Aim adjustment may be necessary if it is difficult to see lane markers (for horizontal aim), or if oncoming drivers flash their high beams at you (for vertical aim). If you believe your headlamps need to be re-aimed, we recommend that you take it to p u r dealer for se!-vice; however, it is possib!e for you to re-aim your headlamps as described in the following procedure. Notice: To make sure your headlamps are aimed properly, read all the instructions before beginning. Failure to follow these instructions could cause damaue to headlamp parts. If necessary, pads may be used on an uneven surface. The vehicle should not have any snow, ice or mud attached to it. The vehicle should be fully assembled and all other work stopped while headlamp aiming is being done. c I nere shouici not be any cargo or ioading of the vehicle, except it should have afull tank of fuel and one person or 160 Ibs (75 kg) on the driver's seat. T I Close all doors. Tires should be properly inflated. Rn& the \mhicle tn stahili7e the s1Is;nension~ 5-49