P0328
DTC P0324, P0326, P0327, P0328, P0331, P0332, or P0333
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions) provides an overview of each diagnostic category.
DTC Descriptors
DTC P0324
- Knock Sensor (KS) Performance
DTC P0326
- Knock Sensor (KS) 1 Performance
DTC P0327
- Knock Sensor (KS) 1 Circuit Low Voltage
DTC P0328
- Knock Sensor (KS) 1 Circuit High Voltage
DTC P0331
- Knock Sensor (KS) 2 Performance
DTC P0332
- Knock Sensor (KS) 2 Circuit Low Voltage
DTC P0333
- Knock Sensor (KS) 2 Circuit High Voltage
Diagnostic Fault Information
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 KS is located on the intake side of the engine block. The KS produces an AC voltage signal that varies depending on the vibration level during engine operation. The ECM receives the KS signal through 2 isolated signal circuits. The ECM adjusts the spark timing based on the amplitude and the frequency of the KS signal.
Conditions for Running the DTC
P0324
This DTC runs continuously when:
* The engine speed is greater than 1,600 RPM.
* The engine load is greater than a calibrated amount.
* DTCs P0326 or P0331 are not set.
P0326 and P0331
These DTCs run continuously when:
* The engine is running
* DTCs P0121, P0122, or P0123 are not set
P0327, P0328, P0332, P0333
These DTCs run continuously when:
* The engine coolant temperature (ECT) is warmer than -40°C (-40°F)
* The engine run time is greater than 1 s.
Conditions for Setting the DTC
P0324
The ECM has detected an internal circuitry fault.
P0326 and P0331
* The KS signal indicates an excessive engine knock is present.
* The ECM commanded spark retard at a given engine load and speed is more than the calibrated value.
* The above conditions exist for up to 6 s.
P0327, P0328, P0332, and P0333
The KS signal circuits are shorted to ground or power.
Action Taken When the DTC Sets
DTCs P0324, P0326, P0327, P0328, P0331, P0332, and P0333 are Type B DTCs.
Conditions for Clearing the MIL/DTC
DTCs P0324, P0326, P0327, P0328, P0331, P0332, and P0333 are Type B DTCs.
Diagnostic Aids
* 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.
Reference Information
Schematic Reference
Engine Controls Schematics ([1][2]Electrical Diagrams)
Connector End View Reference
Component Connector End Views (Connector Views)
Electrical Information Reference
* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)
* Measuring Frequency (Measuring Frequency)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Powertrain Diagnostic Trouble Code (DTC) Type Definitions)
Scan Tool Reference
Control Module References (Programming and Relearning) for scan tool information
Circuit/System Testing
P0324
* If P0327, P0328, P0332, or P0333 are also set, preform those diagnostics first.
* This DTC indicates an internal ECM circuitry failure. Replace the K20 ECM.
P0327, P0328, P0332, and P0333
Note: If the knock sensor lead is damaged in any way, replace the knock sensor.
1. Ignition OFF. Disconnect the appropriate B68 KS harness connector.
2. Measure for 2-5 volts between each of the following circuits and ground on the ECM side of the harness connector:
* The KS signal circuit, terminal A
* The KS signal circuit, terminal B
• If less than the specified range, test the circuits for a short to ground or an open/high resistance. If the circuits test normal, replace the K20 ECM.
• If greater than the specified range, test the circuits for a short to voltage. If the circuits test normal, replace the K20 ECM.
3. If the circuits test normal, replace the B68 knock sensor.
P0326 and P0331
Important: If DTC P0335 or P0336 are also set, diagnose those DTCs first.
* Inspect for a loose or broken vehicle accessory or accessory bracket.
* Inspect for excessive engine mechanical noise.
Component Testing
1. Connect the DMM between the KS signal circuit terminal A and the KS signal circuit terminal B on the sensor side of the KS harness connector.
2. Set the DMM to the 400 mV AC hertz scale and wait for the DMM to stabilize at 0 Hz.
Note: DO NOT tap on plastic engine components.
3. Tap on the engine block with a non-metallic object near the KS while observing the signal indicated on the DMM.
4. The DMM should display a fluctuating frequency while tapping on the engine block.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Knock Sensor Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for ECM replacement, setup, and programming
* Symptoms - Engine Mechanical (Symptoms - Engine Mechanical)
* Symptoms - Engine Controls (Symptoms - Engine Controls)