P0325

Diagnostic Chart:

Wiring Diagram:

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 that is an internal part of the PCM. The amplitude and frequency of the AC voltage signal is dependent upon the knock level being detected. The PCM will then retard the spark timing based on signals from the KS module.

Conditions for Setting the DTC

^ Engine run time is greater than 20 seconds.

^ Engine Coolant Temperature (ECT) is greater than 56°C (131°F).

^ KS instantaneous voltage is less than 1.0 V.

^ Engine speed is above 2200 RPM.

^ MAP is greater than 60 kPa.

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.

^ Coolant fan turns ON.

^ The PCM will default to 6 degrees timing.

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.

^ DTC(s) can be cleared by using the scan tool.

Diagnostic Aids

^ Check and correct any abnormal engine noise before using the diagnostic table.

^ Any circuitry, that is suspected as causing the complaint, should be thoroughly checked for the following conditions:

- Backed out terminals

- Improper mating

- Broken locks

- Improperly formed

- Damaged terminals

- Poor terminal to wiring connections

- Physical damage to the wiring harness

Test Description

Number(s) below refer to the step number(s) on the Diagnostic Table.

1. The Powertrain OBD System Check prompts the technician to complete some basic checks and store the freeze frame and failure records data on the scan tool if applicable. This creates an electronic copy of the data taken when the malfunction occurred. The information is then stored on the scan tool for later reference.

2. It the conditions for the test as described above are met, a DTC P0325 will set and MIL will illuminate.

4. If the engine has an internal knock or audible noise that causes a knocking type noise on the engine block, the knock sensor may be responding to the noise.

6. Checking the internal resistance of the knock sensor or the wiring to the knock sensor is OK.

7. Any circuitry, that is suspected as causing the complaint, should be thoroughly checked for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, poor terminal to wiring connections or physical damage to the wiring harness.

8. The replacement PCM must be programmed and the crankshaft po5ition system variation procedure must be preformed. Refer to the latest Techline procedure for PCM reprogramming and also refer to Powertrain Control Module for the Crankshaft Position System Variation Procedure.