2010 Cadillac CTS Owner's Manual - Page 336

9-36 Vehicle Care The top edge of the cut-off should be positioned at the bottom edge of the horizontal tape line. Notice: Do not cover a headlamp to improve beam cut-off when aiming. Covering a headlamp may cause excessive heat build-up which may cause damage to the headlamp. 6. Turn on the low-beam headlamps and place a piece of cardboard or equivalent in front of the headlamp not being aimed. This should allow only the beam of light from the headlamp being aimed to be seen on the flat surface. Driver Side Shown 7. Locate the vertical headlamp aiming screws, which are under the hood near each headlamp assembly. They are covered by a rubber caps. The adjustment screw can be turned with a 6 mm hex driver. 8. Turn the vertical aiming screw until the headlamp beam is aimed to the horizontal tape line. Turn it clockwise or counterclockwise to raise or lower the angle of the beam. 9. Make sure that the light from the headlamp is positioned at the bottom edge of the horizontal tape line. The lamp on the left (A) shows the correct headlamp aim. The lamp on the right (B) shows the incorrect headlamp aim. 10. Repeat Steps 7 through 9 for the opposite headlamp.