GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Generic 🢒 2008 🢒 Unit Repair 🢒 DTC 🢒 DTC P0324 or P0326

Diagnostic Instructions
    • Perform the Powertrain On Board Diagnostic (OBD) System Check 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 Descriptor

DTC P0324: Knock Sensor (KS) Module Performance

DTC P0326: Knock Sensor (KS) Performance

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

P0324

DTC P0324 runs continuously when the engine speed is greater than or equal to 1,500 RPM and the engine load is greater than a calibrated amount.

P0326

    • DTCs P0120, P0121, P0122, or P0123 are not set
    • The engine speed is greater than or equal to 500 RPM
    • The MAP is greater than 55 kPa
    • DTC P0326 runs continuously when the above conditions are met.

Conditions for Setting the DTC

P0324

The ECM has detected an internal circuitry fault

P0326

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

Action Taken When the DTC Sets

DTCs P0324 and P0326 are Type B DTCs.

Conditions for Clearing the DTC

DTCs P0324 and P0326 are Type B DTCs.

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

    •  Engine Control Module Connector End Views
    •  Engine Controls Connector End Views

Electrical Information Reference

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

DTC Type Reference

Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Engine Control Module Scan Tool Information

Circuit/System Verification
  1. Engine idling, observe the DTC information with a scan tool. Verify DTCs P0325, P0327, P0328, P0330, P0332, or P0333 are not set.
    2. ⇒If any of the above DTCs are set refer to DTC P0325, P0327, P0328, P0330, P0332, or P0333 for further diagnosis.
  2. Engine idling, observe the DTC information with a scan tool. DTC P0324 or P0326 should not set.
    3. ⇒If DTC P0324 is set, replace the ECM.
  3. 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
  1. Verify that there is no abnormal engine mechanical noise.
    2. ⇒If an engine mechanical noise is present, repair as necessary.
  2. Inspect for a loose or broken engine mount, engine mounted accessory, or accessory mounting bracket.
    3. ⇒If a condition is located, repair as necessary.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Engine Control Module Replacement for ECM replacement, setup, and programming