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DTC P0325, P0326, P0327, or P0328 - LE5, LE9

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 Circuit

DTC P0326: Knock Sensor Performance

DTC P0327: Knock Sensor Circuit Low Voltage

DTC P0328: Knock Sensor Circuit High Voltage

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Knock Sensor Signal

P0327

P0325

P0328

P0326

Circuit/System Description

The knock sensor 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 knock sensor is located on the intake side of the engine block. The knock sensor produces an AC voltage signal that varies depending on the vibration level during engine operation. The ECM receives the knock sensor signal through 2 isolated signal circuits. The ECM adjusts the spark timing based on the amplitude and the frequency of the knock sensor signal.

Conditions for Running the DTC

P0325

This DTC runs continuously when:

    • The engine speed is at least 1,500 RPM.
    • The engine coolant temperature (ECT) is warmer than -40°C (-40°F).
    • The engine run time is at least 1 s.
    • DTCs P0326, P0327 or P0328 are not set.

P0326

This DTC runs continuously when:

    • The engine speed is at least 600 RPM.
    • The manifold absolute temperature (MAP) is at least 25 kPa.
    • DTCs P0068, P0106, P0107, P0108, P0120, P0121, P0122, P0123, P0220, P0222, P0223, P0606, P1516, P2101, P2135, or P2176 or are not set.

P0327, P0328

This DTC run continuously when:

    • The engine coolant temperature (ECT) is warmer than -40°C (-40°F).
    • The engine oil temperature is colder than 150°C (302°F).
    • The engine run time is at least 1 s.

Conditions for Setting the DTC

P0325

The knock sensor signal circuits are open or shorted together for 6 s.

P0326

    • The knock sensor 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 6 s.

P0327 and P0328

The knock sensor signal circuits are shorted to ground or power.

Action Taken When the DTC Sets

DTC P0325, P0326, P0327, and P0328 are Type B DTCs.

Conditions for Clearing the MIL/DTC

DTC P0325, P0326, P0327, and P0328 are Type B DTCs.

Diagnostic Aids
    • Inspect the knock sensor for physical damage. A knock sensor that is dropped or damaged may cause a DTC to set.
    • Inspect the knock sensor for proper installation. A knock sensor that is loose or over torqued may cause a DTC to set. The knock sensor should be free of thread sealant.
    • The knock sensor 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

Description and Operation

Electronic Ignition System Description

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

P0325, P0327 and P0328

    Note: If the knock sensor lead is damaged in any way, replace the knock sensor.

  1. Ignition ON, engine OFF.
  2. Disconnect the B68 knock sensor harness connector.
  3. Measure for 2-5 V between each of the following circuits and ground on the engine ECM side of the harness connector:
    4. • Signal circuit, terminal A
    • 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.
  4. If the circuits test normal, replace the B68 knock sensor.

P0326

       Note: If DTC P0327, P0328, P0335, 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.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Knock Sensor Replacement : LE5, LE9 Or LAF → LD9
    •  Symptoms - Engine Controls
    •  Symptoms - Engine Mechanical : LE5 or LE9
    • Control Module References for ECM replacement, setup, and programming
   


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