Possible causes

– Faulty knock sensor
– Knock sensor circuit poor electrical connection
– Knock sensor harness is open or shorted
– Faulty Powertrain Control System (PCM)

Tech notes

The P0325 code means that the Knock Sensor is not working properly. Problems with the knock sensor will not cause an engine performance problems. Replacing the knock sensor usually takes care of the problem.

When is the code detected?

When the Knock Sensor (KS) system is malfunctioning, the KS circuit voltage going to the Powertrain Control System (PCM) goes low. The PCM interprets this low signal as spark knock and will set the P0325 code.

Symptoms

– Engine Light ON (or Service Engine Soon Warning Light)
– Possible Lack/Loss of Power

P0325 BUICK Description

The Knock Sensor (KS) system monitors both knock sensors in order to determine if detonation is present. If the KS system determines that excessive knock (detonation) is present, the Powertrain Control System (PCM) retards the spark timing based on the signals from the KS system. When knock is present, the KS system voltage input signal to the PCM goes low. The PCM then retards timing until no knock is present.