2006 Cadillac CTS Owner's Manual - Page 320

How to Check Lubricant What to Use Refer to the Maintenance Schedule to determine what kind of lubricant to use. See Recommended Fluids and Lubricants on page 6-13. Headlamp Aiming The vehicle has a visual optical headlamp aiming system. The aim has been preset at the factory and should need no further adjustment. However, if the vehicle is damaged in an accident, the headlamp aim may be affected and adjustment may be necessary. If oncoming vehicles flash their high beams at you, this may also mean the vertical aim needs to be adjusted. To get an accurate reading, the vehicle should be on a level surface. If the level is below the bottom of the filler plug hole, located on the rear axle, you'll need to add some lubricant. Add enough lubricant to raise the level to the bottom of the filler plug hole. It is recommended that the vehicle is taken to your dealer for service if the headlamps need to be re-aimed. It is possible however, to re-aim the headlamps as described in the following procedure. 5-50