Diagnostic Instructions
DTC Descriptors
DTC P0325: Knock Sensor (KS) Circuit Bank 1
DTC P0327: Knock Sensor (KS) Circuit Low Voltage Bank 1
DTC P0328: Knock Sensor (KS) Circuit High Voltage Bank 1
DTC P0330: Knock Sensor (KS) Circuit Bank 2
DTC P0332: Knock Sensor (KS) Circuit Low Voltage Bank 2
DTC P0333: Knock Sensor (KS) Circuit High Voltage Bank 2
Circuit/System Description
The knock sensor (KS) system 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 ECM monitors 2 separate KS, one on each
side of the engine block. Each KS produces an AC voltage that varies, depending on the vibration levels detected during engine operation. The ECM receives the KS signal through 2 isolated signal circuits for each KS. The ECM adjusts the spark timing based on
the amplitude and frequency of each KS signal.
Conditions for Running the DTC
| • | The engine run time is greater than 1 second. |
| • | The engine coolant temperature (ECT) is greater than -40°C (-40°F). |
| • | The DTCs run continuously once the above conditions are met. |
Conditions for Setting the DTC
The ECM detects an incorrect KS signal.
Action Taken When the DTC Sets
| • | DTC P0325, P0327, P0328, P0330, P0332, and P0333 are Type B DTCs. |
| • | The ignition timing is retarded to reduce the potential of engine damaging spark knock. |
Conditions for Clearing the DTC
DTC P0325, P0327, P0328, P0330, P0332, and P0333 are Type B DTCs.
Diagnostic Aids
The following conditions could also set this DTC:
| • | Inspect the KS for physical damage. A KS that is dropped or damaged may cause a DTC to set. |
| • | Inspect the KS for proper installation. A KS that is loose or over torqued may cause a DTC to set. The KS should be free of thread sealant. The KS mounting surface should be free of burrs, casting flash, and foreign material. |
| • | The KS must be clear of hoses, brackets, and engine electrical wiring. |
| • | An electromagnetic interference (EMI) condition on the shielded ground circuit |
Reference Information
Schematic Reference
Engine Controls Schematics
Connector End View Reference
Electrical Information Reference
DTC Type Reference
Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Engine Control Module Scan Tool Information
Circuit/System Verification
- Engine idling, observe the DTC information with a scan tool. DTCs P0325, P0327, P0328, P0330, P0332, or P0333 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.
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the appropriate KS.
- Ignition ON, test for 2-3 volts between each of the following circuits and ground:
| • | The KS signal circuit, terminal A |
| • | The KS signal circuit, terminal B |
| ⇒ | If less than the specified range, test the appropriate circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM. |
| ⇒ | If greater than the specified range, test the appropriate circuit for a short to voltage. If the circuit tests normal, replace the ECM. |
- If all circuits test normal, replace the KS sensor.
Repair Instructions
Perform the
Diagnostic Repair Verification
after completing the diagnostic procedure.
