DI–71 DIAGNOSTICS – ENGINE DI38A–03 DTC P0325 Knock Sensor 1 Circuit Malfunction CIRCUIT DESCRIPTION The knock sensor is fitted to the cylinder block to detect engine knocking. This sensor contains a piezoelec- tric element which generates a voltage when it becomes deformed, which occurs when the cylinder block vibrates due to knocking. If engine knocking occurs, ignition timing is retarded to suppress it. DTC No. DTC Detecting Condition Trouble Area