The KS sensors(Knock Sensor) inform the ECM (Engine Control module) when one or more of the engine cylinders are knocking, i.e. when the air/fuel mixture explodes, it does not provide the necessary energy which causes problems for the engine if this happens for a long time.
The Engine Control Module (ECM) uses this information to tune the engine. If the Knock Sensor (KS) in bank 2 generates a low output voltage, possibly 0.5 volts, the DTC code P0332 is activated.