Diagnostic Aids

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2018 GMC Yukon XL, 2018 GMC Yukon, 2018 Chevrolet Tahoe, 2018 Chevrolet Suburban, and 2018 Cadillac Escalade ESV. However, it is still accessible from the selected car via links, so may be relevant.

Inspect the knock sensor for physical damage. A damaged sensor may cause a DTC to set.
The knock sensor mounting surface should be free of burrs, casting flash, and foreign material.
Tightening the retaining bolt too much or simply dropping the knock sensor on the ground can damage it.