Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
DTC Descriptors
DTC P0325: Knock Sensor (KS) Module Performance - Non European EmissionsDTC P0325: Knock Sensor (KS) Circuit - European Emissions
Circuit/System Description
The knock sensor (KS) enables the engine control module (ECM) to control the ignition timing for the best possible performance while protecting the engine from potentially damaging levels of detonation. The KS produces an AC voltage signal that varies depending on the vibration level during engine operation. The ECM adjusts the spark timing based on the amplitude and the frequency of the KS signal. The ECM receives the KS signal through a signal circuit . The ECM supples a ground circuit to the KS through a low reference circuit . The ECM also supplies a shielded ground circuit to the KS. The ECM learns a KS noise level at idle and uses calibrated values for the rest of the engine speed range. The ECM should monitor a normal KS signal within the noise channel.
Conditions for Running the DTC
| • | DTCs P0106, P0107 and P0108 are not set. |
| • | The engine speed is greater than 1,600 RPM. |
| • | The engine coolant temperature (ECT) is more than 50°C (122°F) for Euro III Emissions or 66°C (151°F) for Euro IV Emissions. |
| • | The manifold absolute pressure (MAP) is between 10-50 kPa which depends on engine speed. |
| • | DTC P0325 runs continuously once the above conditions are met. |
Conditions for Setting the DTC
P0325 - Non European Emissions
The control module has detected an internal circuitry fault.
P0325 - European Emissions
The ECM detects an incorrect KS signal for greater than 4 seconds.
Action Taken When the DTC Sets
DTC P0325 is a Type C DTC.
Conditions for Clearing the DTC
DTC P0325 is a Type C DTC.
Reference Information
Schematic Reference
Description and Operation
Knock Sensor (KS) System Description
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
- Ignition ON, observe the DTC information with a scan tool. DTC P0325 should not set.
- Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
| ⇒ | If DTC P0325 failed this ignition, for a Non European Emissions system, test or replace the ECM. |
Circuit/System Testing - European Emissions Only
- Ignition OFF, disconnect the harness connector at the KS sensor.
- Ignition ON, connect a test lamp between the signal circuit terminal 1 and ground. The test lamp should not illuminate.
- Connect a test lamp between the signal circuit terminal 1 and 12 volts. The test lamp should not illuminate.
- Ignition OFF, connect a DMM between the signal circuit terminal 1 and the low reference circuit terminal 2.
- Test for 90-110K ohms of resistance between the signal circuit terminal 1 and the low reference circuit terminal 2.
- If all circuits test normal, test or replace the KS sensor.
Important: If the knock sensor lead is damaged in any way, replace the knock sensor.
| ⇒ | If the test lamp illuminates, test the signal circuit for a short to voltage. If the circuit tests normal, replace the ECM. |
| ⇒ | If the test lamp illuminates, test the signal circuit for a short to ground. If the circuit tests normal, replace the ECM. |
| ⇒ | If not within the specified range, test the circuits for an open/high resistance. If the circuits test normal, replace the ECM. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for engine control module replacement, setup, and programming
