P0325

Knock Sensor (KS) Circuit:

Circuit Description
The knock sensor system is used to detect engine detonation. The knock sensor produces an AC voltage signal. This signal is then sent to the Knock Sensor (KS) module. The amplitude and frequency of the AC voltage signal is dependent upon the knock level being detected. The Powertrain Control Module (PCM) will then retard the spark timing based on signals from the KS module.

Conditions For Setting The DTC
- The KS voltage is less than 0.19V or greater than 4.99V.
- The engine speed is between 2200 RPM and 6375 rpm.
- The Throttle Position (TP) angle is greater than 5%.
- One or more of the following DTCs are not set P0117, P0118, P0122, P0123.
OR
- The knock is present for greater than 2.3 seconds over a 6 second interval.
- One or both of the following DTCs are not set P0122, P0123.

Action Taken When the DTC Sets
- The Malfunction Indicator Lamp (MIL) will illuminate.
- The PCM will record operating conditions at the time the diagnostic fails. This information will be stored in the Freeze Frame and Failure Records buffers.
- A history DTC is stored.

Conditions for Clearing the MIL/DTC
- The MIL will turn "OFF" after three consecutive ignition cycles in which the diagnostic runs without a fault.
- A history DTC will clear after 40 consecutive warm up cycles without a fault.
- DTCs can be cleared by using a scan tool.

Diagnostic Aids
Correct any abnormal engine noise before using the diagnostic Table.

DTC P0325 - Knock Sensor (KS) Circuit (1 Of 2):

DTC P0325 - Knock Sensor (KS) Circuit (2 Of 2):

Test Description
Numbers below refer to the step numbers on the Diagnostic Table.
1. The OBD System Check prompts the Technician to complete some basic checks and store the Freeze Frame Data and the Failure records on the scan tool if applicable. This creates an electronic copy of the data taken when the fault occurred. This information on the scan tool can be referred to later
2. Whenever the conditions for the test as described above are met, a DTC P0325 will set and MIL will illuminated.
4. The scan tool displays knock sensor activity in counts, approximately 35-50 at idle. The counts should increase when engine speed is increased and the counts should decrease when engine speed is decreased.
9. Before replacing the PCM, check terminals for improper mating, broken locks, or physical damage to the wiring harness. Replacement PCM must be reprogrammed. Refer to the latest Techline information for programming procedures.
11. Checking the internal resistance of the knock sensor verifies if the knock sensor is operating properly.