P0327
DTC P0327 Knock Sensor (KS) Circuit
Circuit Description
The control module uses the knock sensors (KS) in order to detect engine detonation. Ignition control (IC) spark timing is retarded based on the KS signal input when spark knock is detected.
The control module monitors normal engine background noise during warm engine operation. It stores these noise values for comparison to the current knock sensor signal in order to help discriminate between normal engine noise and knock. If the amount of noise is below the minimum stored noise value, this diagnostic trouble code (DTC) will set.
Conditions for Running the DTC
- No active ECT sensor DTCs.
- No active TP sensor DTCs.
- The timing retard is 0 degrees or less.
- The system voltage is between than 10-17 volts.
- The ECT is 60°C (140° F) or more.
- The engine run time is 120 seconds or more.
- The knock sensor noise is less than 3 counts.
- The engine speed is between 2000-3000 RPM.
- The throttle position is more than 6 percent.
Conditions for Setting the DTC
The difference between the actual noise value and the learned minimum noise value is less than 50 counts or more than 200 counts.
Action Taken When the DTC Sets
- The control module illuminates the malfunction indicator lamp (MIL) if a failure is detected during 2 consecutive key cycles.
- The control module sets the DTC and records the operating conditions at the time the diagnostic failed. The failure information is stored in the scan tool Freeze Frame/Failure Records.
Conditions for Clearing the MIL or DTC
- The control module turns OFF the MIL after 3 consecutive drive trips when the test has run and passed.
- A history DTC will clear if no fault conditions have been detected for 40 warm-up cycles. A warm-up cycle occurs when the coolant temperature has risen 22°C (40°F) from the startup coolant temperature and the engine coolant reaches a temperature that is more than 70°C (158°F) during the same ignition cycle.
- Use a scan tool in order to clear the DTCs.
Diagnostic Aids
Check for the following conditions:
- A misrouted harness. Inspect the knock sensor harness in order to ensure that it is not routed too close to high voltage wires such as spark plug leads.
Notice: Replacement components must be the correct part number for the application. Components requiring the use of the thread locking compound, lubricants, corrosion inhibitors, or sealants are identified in the service procedure. Some replacement components may come with these coatings already applied. Do not use these coatings on components unless specified. These coatings can affect the final torque, which may affect the operation of the component. Use the correct torque specification when installing components in order to avoid damage.
- An improperly torqued knock sensor. Torque the knock sensor to 19 Nm (14 ft. lbs.).
Review the Fail Records vehicle mileage since the diagnostic test last failed in order to determine how often the conditions occur that caused the DTC to set . This may assist in diagnosing the condition.
An intermittent may be caused by any of the following conditions:
- A poor connection.
- Rubbed through wire insulation.
- A broken wire inside the insulation.
Thoroughly check any circuitry that is suspected of causing the intermittent complaint.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
2. Ensures that the condition is present.
5. Ensures that the knock sensor is capable of detecting detonation. Striking the lift bracket with a non-metallic object should produce a signal that the knock sensor should detect.
7. Ensures that the 5 volt reference is near the specified value without being more than 5.2 volts.
