2001 Cadillac DeVille Owner's Manual - Page 347

Headlamp Aiming If your vehicle is damaged in an accident, the headlamp aim may be affected. Aim adjustment to the low beam 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 your vehicle to your dealer for service. However, it is possible for you to re-aim your headlamps as described in the following procedure. NOTICE: Your vehicle has a visual optical headlamp aiming system equipped with horizontal aim indicators. The aim has been pre-set at the factory and should need no further adjustment. This is true even though your horizontal aim indicators may not fall exactly on the "0" (zero) marks on their scales. To make sure your headlamps are aimed properly, read all the instructions before beginning. Failure to follow these instructions could cause damage to headlamp parts. 6-39