Circuit Description

Knock sensors are located under intake manifolds, on the inside of the cylinder heads. Knock sensors generate voltage when engine block vibrates due to knocking. If engine knocks, ECM will retard ignition timing. If DTC is set, ECM will operate in fail-safe mode (maximum timing retardation). DTC are set when there is no knock sensor signal to ECM with engine speed of 1700-5400 RPM. DTC P0325 is for knock sensor No. 1 on right side of cylinder block. DTC P0330 is for knock sensor No. 2 on left side of cylinder block. Possible causes are:

• Open or short in knock sensor circuit.
• Knock sensor (loose).
• ECM.