P0327
CIRCUIT DESCRIPTIONThe knock sensors (KS) produce an AC signal under all engine operating conditions. When the engine is running, the powertrain control module (PCM) learns a minimum and maximum frequency of normal engine noise. The KS system monitors both knock sensors in order to determine if knock is present. If the KS system determines that excessive knock is present, the PCM retards the spark timing based on the signals from the KS. The PCM continues to retard timing until no knock is present. If the PCM detects that the frequency is out of the normal range, DTC P0327 or P0332 will set.
CONDITIONS FOR RUNNING THE DTC
- DTCs P0116, P0117, P0118, P0122, P0123, P0125, or P0128 are not set.
- The minimum noise level must be learned. The minimum noise level is learned when the following conditions are met:
- The engine coolant temperature (ECT) is more than 60°C (140°F).
- The engine RPM is between 475-975 for 10 seconds.
- The engine speed is between 1,500-3,000 RPM.
- The manifold absolute pressure (MAP) is less than 45 kPa.
- The engine run time is more than 10 seconds.
- The ignition voltage is more than 10 volts.
CONDITIONS FOR SETTING THE DTC
The PCM detects that the affected KS signal is less than the expected amount for more than 9 seconds.
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
- Inspect the KS for proper installation. A knock sensor that is loose or over torqued may cause the DTC to set.
IMPORTANT: If the KS is dropped, the sensor must be replaced.
- If DTCs P0327 and P0332 are set at the same time, inspect for poor connections at the KS harness jumper, located at the left rear side of the intake manifold.
- For an intermittent, refer to Intermittent Conditions. Intermittent Conditions
TEST
