P0327

DTC P0327

CIRCUIT DESCRIPTION
The knock sensor (KS) system is used in order to detect any engine detonation, or spark knock. The engine control module (ECM) will retard the spark timing based on the signals from the KS. The knock sensors produce an AC voltage that is sent to the ECM. The amount of AC voltage produced is proportional to the amount of knock.

An operating engine produces a normal amount of engine mechanical vibration, or noise. The KS will produce an AC voltage signal from this noise. When the engine is operating, the ECM will learn the minimum and maximum amplitude of the noise the engine produces. If the ECM detects that this amplitude is below the normal operating range, DTC P0327 or P0332 will set.

CONDITIONS FOR RUNNING THE DTC
- The engine coolant temperature (ECT) sensor is more than 40°C (104°F).
- The engine speed is more than 2000 RPM.
- The volumetric efficiency is more than 40 percent.

CONDITIONS FOR SETTING THE DTC
The KS signal is below the normal operating range or the KS signal is not present.

ACTION TAKEN WHEN THE DTC SETS
- The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
- The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

CONDITIONS FOR CLEARING THE MIL/DTC
- The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
- A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
- A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
- Clear the MIL and the DTC with a scan tool.

DIAGNOSTIC AIDS
- The KS must be torqued correctly. Refer to Knock Sensor (KS) 1 Replacement and Knock Sensor (KS) 2 Replacement.
- The mounting between the sensor and engine must be free of burrs, casting flash, and foreign material.
- The KS head must be clear from hoses, brackets, and engine wiring.
- If the KS is dropped, the KS must be replaced.
- If the sensor lead is damaged in any way, the sensor must be replaced.
- For an intermittent condition, refer to Intermittent Conditions. Diagnostic Strategies

TEST DESCRIPTION

Steps 1-4:

Steps 5-12:

The number below refers to the step number on the diagnostic table.
3. This step tests for continuity in the KS circuit. An out of limit (OL) on the DMM display indicates an open in either the wiring or the ECM.