Diagnostic Aids

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2011 GMC Yukon XL, 2011 GMC Yukon, 2011 Chevrolet Tahoe, 2011 Chevrolet Suburban, and 2011 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.

Installation of aftermarket replacement speakers, additional speakers/subwoofers, or aftermarket exhaust systems can cause undesirable behavior of the active noise cancellation system.
The noise reduction microphones have foam blocks above them to seal the microphones and aid in the reduction of headliner vibration. Missing or out of place foam blocks can impact system performance.