Knock Sensor: Testing and Inspection

If the KS module is missing or faulty causing a continuous knock condition to be indicated, the PCM will set DTC P0325.

The scan tool has four data display parameters available for diagnosing the KS system. The four parameters are described as follows:

^ KS Activity is used to monitor the input signal from the knock sensor. This parameter will display Yes while detonation is being detected.
^ Knock Retard is the indication of how much the PCM is retarding the spark. The PCM will retard spark in response to any of the following conditions:
- An active knock sensor system DTC is set.
- The knock sensor signal is indicating detonation.
- The traction control system desired torque signal is indicating a traction control event.
^ KS Minimum Learned Noise indicates the minimum level that the PCM has detected on the noise channel while the noise level was being learned. The PCM uses this parameter for diagnosis of the KS system. If the PCM determines that an abnormally high learned minimum or maximum noise level is being experienced, a DTC P0326 will set.
^ KS Noise Channel indicates the current voltage level being monitored on the noise channel. The PCM monitors the noise channel level to ensure that the KS sensors, the KS module, and the related wiring is operating correctly. If the voltage level on the KS noise channel circuit is below the range considered normal, DTC P0327 will set, indicating a fault in the KS circuit or one of the knock sensors.

DTCs P0325, P0326, and P0327 are designed to diagnose the KS module, the knock sensors, and related wiring, so problems encountered with the KS system should set a DTC. However, if no DTC was set but the KS system is suspect because detonation was the customer's complaint, refer to Diagnosis by Symptoms.