Diagnostic Trouble Code (DTC) Troubleshooting - DTC P0325/P0326

DESCRIPTION AND OPERATION

The knock sensor (KS) is installed on the cylinder block and detects abnormal combustion (knock) of fuel in the engine cylinders. Cylinder block vibration caused by knock creates pressure acting on the piezoelectric crystal in the sensor. As a result, the vibration is converted into a signal (voltage) proportional to its intensity. The ECM uses this signal to retard ignition timing until knock disappears.

DTC SET CONDITIONS

The ECM will store a DTC (MIL will not illuminate) if the knock sensor signal voltage drops below 650 mV during a 4-second check within two driving cycles, when the following conditions are met:

• Crankshaft is not being cranked by the starter.

• Engine speed above 3000 rpm.

• Engine coolant temperature above 40 °C.

• Engine load (injector pulse width) is greater than 2 msec.

This DTC indicates abnormal vibration data from the knock sensor (KS) or the ECM during normal engine operation.

WIRING DIAGRAM

INSPECTION PROCEDURE

INSPECTION PROCEDURE