P0327
CIRCUIT DESCRIPTIONThe Powertrain Control Module (PCM) uses a Knock Sensor (KS) to detect engine detonation (spark knock). The knock sensor produces an AC signal at all engine speeds, and loads. The PCM makes adjustments to the spark timing based on the amplitude and frequency of the KS signal.
The PCM uses the knock sensor to determine the amount of normal engine noise (noise channel) for a wide range of engine speeds and loads. The PCM compares the actual knock sensor signal to the learned noise channel. The PCM uses the noise channel to diagnose the knock sensor and related wiring. If the PCM detects a loss of the noise channel, this DTC will set.
CONDITIONS FOR RUNNING THE DTC
^ The engine speed is more than 3000 RPM.
^ The system voltage is more than 11 volts.
CONDITIONS FOR SETTING THE DTC
The PCM detects a KS signal less than 0.4 volt.
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.
^ Use a scan tool in order to clear the MIL and the DTC.
DIAGNOSTIC AIDS
If the conditions is intermittent, refer to Intermittent Conditions. Intermittent Conditions
TEST
