For 1990-2009 cars

### 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 Descriptor

DTC P0324: Knock Sensor (KS) System Performance
DTC P0326: Knock Sensor (KS) Performance
DTC P06B6: Internal Control Module Knock Sensor Processor Performance

### Circuit/System Description

The knock sensor (KS) 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 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 a signal circuit. The ECM supples a ground circuit to the KS through a low reference circuit. The ECM also supplies a shielded ground circuit to the KS. The ECM learns a KS noise level at idle and uses calibrated values for the rest of the engine speed range. The ECM should monitor a normal KS signal within the noise channel.

### Conditions for Running the DTC

• | The engine speed is greater than 600 RPM for DTC P0324/P0326.

• | The engine speed is between 600-2,900 RPM for DTC P06B6.

• | The airflow into the engine is between 40-2,000 mg/cylinder.

• | DTCs P0324, P0326, and P06B6 run continuously once the above conditions are met.

### Conditions for Setting the DTC

#### P0324 or P0326

The control module detects an overactive knock sensor.

#### P06B6

The control module detects an internal circuitry fault.

### Action Taken When the DTC Sets

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

### Conditions for Clearing the DTC

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

### Reference Information

#### Description and Operation

Knock Sensor (KS) 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 idling, observe the DTC information with a scan tool. Verify DTC P0327, P0328, and P06B6 is not set.

⇒ | If DTC P0327 or P0328 is set with P06B6, refer to DTC P0325, P0327, or P0328 for further diagnosis.

⇒ | If DTC P06B6 is set, replace the ECM.

2. Ignition OFF, inspect for the following:

• | 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

• | The KS must be clear of hoses, brackets, and engine electrical wiring

• | Inspect for loose accessory brackets

• | Inspect for serpentine belt and tensioner wear

• | Inspect for an engine mechanical condition--Refer to Symptoms - Engine Mechanical

⇒ | If a condition is found, repair as necessary.

3. If there is no mechanical condition, test or replace the KS sensor.
4. 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.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Knock Sensor Replacement

• | Control Module References for ECM replacement, setup, and programming