P0327

This article has been updated with bulletin No. 02-06-04-045


CIRCUIT DESCRIPTION
The knock sensor (KS) produces an AC voltage at all engine speeds and loads. The powertrain control module (PCM) then adjusts the spark timing bases on the amplitude and frequency of the KS signal. The PCM uses the KS signal to calculate the average voltage, then the PCM assigns a voltage value. The PCM checks the KS and related wiring by comparing the actual knock signal to the assigned voltage range. A normal KS signal should within the assigned voltage range. This DTC will set if the KS signal is outside the assigned voltage range or not present.

CONDITIONS FOR RUNNING THE DTC
^ DTCs P0117, P0118, P0122, or P0123 are not set.
^ The ignition voltage is more than 10 volts.
^ The engine coolant temperature (ECT) sensor is more than 70°C (158°F).
^ The engine run time is more than 20 seconds.
^ The manifold absolute pressure (MAP) is more than 60 kPa.
^ The engine speed is between 1,800-6,400 RPM.

CONDITIONS FOR SETTING THE DTC
The KS signal is outside 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) Replacement.
^ The mounting between the sensor and engine must be free of burrs, casting flash, and foreign material.
^ The KS head is clear from hoses, brackets, and engine wiring.
^ If the KS is dropped, it must be replaced.
^ For an intermittent condition, refer to Intermittent Conditions. Intermittent Conditions

TEST DESCRIPTION

Steps 1-8:

Steps 9-14:

The numbers below refer to the step numbers on the diagnostic table.
2. This step verifies a condition is present.
4. This test is checking for continuity in the KS circuit. An out of limit on the DMM display is indicating an open in either the wiring or the PCM.