P0325
DTC P0325 Knock Sensor 1 CircuitDTC P0327 Knock Sensor 1 Circuit Low Input (Bank 1 or Single Sensor)
DTC P0328 Knock Sensor 1 Circuit High Input (Bank 1 or Single Sensor)
DESCRIPTION
DTC Detection Conditions:
A flat type knock sensor (non-resonant type) has a structure that can detect vibrations over a wide band of frequencies: between approximately 6 kHz and 15 kHz.
Knock sensors are fitted onto the engine block to detect engine knocking.
The knock sensor contains a piezoelectric element which generates a voltage when it becomes deformed. The voltage is generated when the engine block vibrates due to knocking. Any occurrence of engine knocking can be suppressed by delaying the ignition timing.
HINT: When any of DTCs P0325, P0327 and P0328 are set, the ECM enters fail-safe mode. During fail-safe mode, the ignition timing is delayed to its maximum retardation. Fail-safe mode continues until the ignition switch is turned OFF.
Reference: Inspection using an oscilloscope.
The correct waveform is as shown.
MONITOR DESCRIPTION
Monitor Strategy:
Typical Enabling Conditions:
Typical Malfunction Thresholds:
If the output voltage transmitted by the knock sensor remains low or high for more than 1 second, the ECM interprets this as a malfunction in the sensor circuit, and sets a DTC.
The monitor for DTCs P0325, P0327 and P0328 begins to run when 5 seconds have elapsed since the engine was started.
If the malfunction is not repaired successfully, either DTC P0325, P0327 or P0328 is set 5 seconds after the engine is next started.
Wiring Diagram:
Step 1:
Step 2-3:
INSPECTION PROCEDURE
HINT: Read freeze frame data using an intelligent tester or OBD II scan tool. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air/fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction.