GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2008 🢒 Enclave 🢒 DTC 🢒 DTC P0324, P0325, P0326, P0327, P0328, P0330, P0332, or P0333

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 P0324: Knock Sensor (KS) Module Performance

DTC P0325: Knock Sensor (KS) Circuit Bank 1

DTC P0326: Knock Sensor (KS) Performance Bank 1

DTC P0327: Knock Sensor (KS) Circuit Low Bank 1

DTC P0328: Knock Sensor (KS) Circuit High Bank 1

DTC P0330: Knock Sensor (KS) Circuit Bank 2

DTC P0332: Knock Sensor (KS) Circuit Low Bank 2

DTC P0333: Knock Sensor (KS) Circuit High Bank 2

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Knock Sensor Signal

P0327, P0328, P0332

P0325, P0330

P0327, P0332

P0326

Low Reference

P0327, P0328, P0332

P0325, P0330

P0328, P0333

P0326

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 sensors are located below each cylinder head on the engine block. 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 2 isolated signal circuits. The ECM learns a minimum KS noise level at idle and uses calibrated values for the rest of the RPM range. The ECM should monitor a normal KS signal within the noise channel.

Conditions for Running the DTC

P0325, P0326, and P0330

    • The engine speed is greater than 1,800 RPM.
    • The manifold absolute pressure (MAP) is greater than 55 kPa.
    • The DTCs run continuously when the above conditions are met.

P0324, P0327, P0328, and P0333

    • The ignition is ON.
    • The DTCs run continuously when the above condition is met.

Conditions for Setting the DTC

P0324

The ECM has detected an internal circuitry fault.

P0325 and P0330

The KS signal circuits are open or shorted together for 5 seconds.

P0326

    • The KS signal indicates an excessive engine knock is present.
    • The ECM has commanded the spark retard to a value, which is greater than the calibrated value, for a specific engine load and speed.
    • The above conditions exist for greater than 5 seconds.

P0327, P0328, P0332, and P0333

The KS signal circuits are shorted to voltage or ground.

Action Taken When the DTC Sets

DTCs P0324, P0325, P0326, P0327, P0328, P0330, P0332 and P0333 are Type B DTCs.

Conditions for Clearing the DTC

DTCs P0324, P0325, P0326, P0327, P0328, P0330, 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

Connector End View Reference

Component Connector End Views

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Testing

P0324

    • Verify that the following DTCs are not set: P0325, P0327, P0328, P0330, P0332, or P0333.
       ⇒If any of the DTCs are set, diagnose them first.
    • This DTC indicates an internal ECM circuitry failure. Replace the ECM.

P0325, P0327, P0328, P0330, P0332, P0333

  1. Ignition ON, engine OFF.
  2. Disconnect the KS harness connector.
  3. Measure for 2-3 volts between each of the following circuits and ground on the ECM side of the harness connector:
    4. • The KS signal circuit, terminal 1
    • The KS signal circuit, terminal 2
    ⇒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 ECM.
    ⇒If greater than the specified range, test the circuits for a short to voltage. If the circuits test normal, replace the ECM.
  4. If the circuits test normal, replace the KS.

P0326

    • 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 1 and the KS signal circuit terminal 2 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.

    3. Important: 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 after completing the diagnostic procedure.

    •  Knock Sensor Replacement - Bank 1
    •  Knock Sensor Replacement - Bank 2
    •  Symptoms - Engine Controls
    •  Symptoms - Engine Mechanical
    •  Control Module References for ECM replacement, setup, and programming