DTC P0325: Knock Sensor Module Circuit: Notes
WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2001 Pontiac Grand Prix, 2001 Pontiac Bonneville, 2001 Chevrolet Monte Carlo, 2001 Chevrolet Impala, and 2001 Buick Regal. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
For circuit reference, see WIRING DIAGRAMS article.