For service and parts needs, visit your dealer. You will receive genuine GM parts and GM-trained and supported service people.
Genuine GM parts have one of these marks:

Vehicle Care
California Proposition 65 WarningHorns
Specifications
Horn Replacement
Preliminary Procedure
Remove the front bumper fascia. Refer to Front Bumper Fascia Replacement.
Horn Nut
Caution: Refer to Fastener Caution in the Preface section.
Tighten
17 N·m (13 lb ft)
Horn
Tip
Disconnect electrical connectors.
St ...
Exterior Lighting Systems Description and Operation
Exterior Lamps
The exterior lighting system consists of the following lamps if equipped:
Headlamps
Daytime Running Lamps (DRL)
Front fog lamps
Rear fog lamps
Park, tail and license lamps
Turn signal lamps
Hazard warning lamps
Repeater lamps
Stop lamps
Backup lamps
Low Beam ...
Hill and Mountain Roads
Driving on steep hills or through mountains is different than driving on flat
or rolling terrain. Tips for driving in these conditions include:
• Keep the vehicle serviced and in good shape.
• Check all fluid levels and brakes, tires, cooling system, and transmission.
• Shift to a lower g ...