Buick Regal: DTC P0324, P0326, P0331, P06B6, or P06B7

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 System Performance

DTC P0326

Knock Sensor 1 Performance

DTC P0331

Knock Sensor 2 Performance

DTC P06B6

Control Module Knock Sensor Processor 1 Performance

DTC P06B7

Control Module Knock Sensor Processor 2 Performance

Diagnostic Fault Information

Circuit/System Description

The knock sensors enable 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 sensors produce an alternating current (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 two knock sensor signals. The ECM receives each knock sensor signal through a dedicated circuit. The ECM learns a minimum knock sensor noise level for all of the engine speed ranges and monitors the normal knock sensor signal. The ECM monitors the internal knock sensor processor test circuits which perform the open circuit diagnostic.

Conditions for Running the DTCs

P0324

• Engine is running for 2 s or greater.
• Engine speed is 8, 500 RPM or less.
• Engine air flow is between 0 - 2000 mg per cylinder.
• The engine coolant temperature (ECT) is -40ºC (-40ºF) or warmer.
• The intake air temperature (IAT) sensor is -40ºC (-40ºF) or warmer.

  AND

• Engine speed is 550 RPM or greater for 300 or more cumulative revolutions.

  OR

• Engine speed is 8500 RPM or greater for 400 or more cumulative revolutions.

P0326 and P0331

• Engine is running for 2 s or greater.
• Engine speed is 8, 500 RPM or less.
• Engine air flow is between 20 - 2000 mg per cylinder.
• The engine coolant temperature (ECT) is -40ºC (-40ºF) or warmer.
• The intake air temperature (IAT) sensor is -40ºC (-40ºF) or warmer.

  AND

• Engine speed is 500 RPM or greater for 200 or more cumulative revolutions.

  OR

• Engine speed is 2000 RPM or greater for 200 or more cumulative revolutions.

  OR

• Engine speed is 8500 RPM or greater for 200 or more cumulative revolutions.

P06B6 and P06B7

• Engine is running for 2 s or greater.
• Engine speed is between 400 - 8, 500 RPM for 150 or more cumulative revolutions.
• Engine air flow is between 20 - 2000 mg per cylinder.

The DTCs run continuously when the above conditions are met.

Conditions for Setting the DTCs

P0324

The ECM detects that either knock sensor signal performance is out of the normal calibrated range due to excessive engine knock on a per cylinder basis.

P0326

The ECM detects that the knock sensor 1 signal performance is out of the normal calibrated range due to a low signal level.

P0331

The ECM detects that the knock sensor 2 signal performance is out of the normal calibrated range due to a low signal level.

P06B6 and P06B7

The ECM has detected a fault in the knock sensor processor open circuit diagnostic internal test circuit.

Action Taken When the DTCs Set

• DTCs P0324, P0326, P0331, P06B6, and P06B7 are Type B DTCs.
• The ignition timing is retarded to reduce the potential of engine damaging spark knock.

Conditions for Clearing the DTCs

DTCs P0324, P0326, P0331, P06B6, and P06B7 are Type B DTCs.

Reference Information

Description and Operation

Electronic Ignition System Description

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

1. Engine Running.

2. Verify DTC P0325, P0327, P0328, P0330, P0332, P0333, P06B6, or P06B7 is not set.

• If DTC P0325, P0327, P0328, P0330, P0332, or P0333 is set with P06B6 or P06B7

Refer to DTC P0325, P0327, P0328, P0330, P0332, or P0333.

• If only DTC P06B6 or P06B7 is set

Replace the K20 Engine Control Module.

• Go to next step: If none of the DTCs are set

3. Ignition OFF.

4. Verify none of the conditions listed below exist:

• B68 Knock Sensor or wiring harness damage.
• Incorrect B68 Knock Sensor installation. Refer to Fastener Specifications.
• B68 Knock Sensor and engine mounting surface burrs, casting flash, and foreign material.
• Close proximity of hoses, brackets, and engine wiring.
• Loose brackets.
• Loose or broken accessory drive belts, brackets, components.
• An engine mechanical condition. Refer to Symptoms - Engine Mechanical.
• Contaminated or poor quality fuel.
• If a condition exists

Repair or replace as necessary.

• Go to next step: If no conditions exist

5. Operate the vehicle within the conditions for running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

• If the DTC sets

Test or replace the appropriate B68 Knock Sensor.

• Go to next step: If the DTC does not set

6. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

• Knock Sensor Replacement (Position 2) or Knock Sensor Replacement (Position 1)
• Control Module References for engine control module replacement, programming, and setup.

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