Diagnostic Aids

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2008 GMC Yukon XL, 2008 GMC Yukon, 2008 Chevrolet Tahoe, 2008 Chevrolet Suburban, and 2008 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.

If diagnosing a Horn - Poor Tone condition, inspect the following:

Debris or water in the horn assembly.
Proper horn mounting hardware torque. Refer to Fastener Tightening Specifications .
Debris in the joint where the horns attach to the vehicle.