DTC will set when the following conditions are present:

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 1997 GMC Yukon, 1997 GMC Suburban, 1997 GMC Pickup, 1997 GMC Cab & Chassis, and 1997 Chevrolet Tahoe. However, it is still accessible from the selected car via links, so may be relevant.

DTC P0327 is not set.
Engine has been running for at least 120 seconds.
System voltage is greater than 10 volts but less than 17.1 volts.
VCM detects a problem with KS module circuitry that causes a continuous knock condition.
Conditions are present for up to .5 second.