Conditions for Setting the DTCs
WARNING: This page is about a different car, the 2017 GMC Acadia. However, it is still accessible from the selected car via links, so may be relevant.
P0324
The ECM detects that either knock sensor signal performance is out of the normal calibrated range due to excessive engine knock on a per cylinder basis.
P0326
The ECM detects that the knock sensor 1 signal performance is out of the normal calibrated range due to a low signal level.
P0331
The ECM detects that the knock sensor 2 signal performance is out of the normal calibrated range due to a low signal level.
P06B6 and P06B7
The ECM has detected a fault in the knock sensor processor open circuit diagnostic internal test circuit.