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 Module Performance
DTC P0327: Knock Sensor Circuit Low Frequency (Bank 1)
DTC P0328: Knock Sensor Circuit High Frequency (Bank 1)
DTC P0332: Knock Sensor Circuit Low Frequency (Bank 2)
DTC P0333: Knock Sensor Circuit High Frequency (Bank 2)

### Circuit/System Description

The knock sensor (KS) is a piezoelectric device that produces an AC voltage of different amplitude and frequency depending on the level of engine mechanical vibration. The KS system monitors the knock sensor in order to determine if detonation or spark knock is present. If the KS system determines that knock is present the engine control module (ECM) retards the spark timing based on the signal from the KS system. The KS produces an AC signal when specific frequencies are detected. The ECM then retards the timing until knock is controlled.

In order to differentiate between normal engine noise and spark knock the ECM samples the KS signal. The ECM samples the KS signal for a certain length of time under different engine speeds and loads during non-cylinder knock events. This sampling is used to determine a range of acceptable normal engine noise.

### Conditions for Running the DTCs

• | Before the ECM can report DTC P0327, P0328, P0332 or P0333 failed, DTCs P0324, P0335, P0336 and P0338 must run and pass.

• | DTCs P0341, P0342, P0343, P0346, P0347, P0348, P0366, P0367, P0368, P0391, P0392 and P0393 are not set.

• | The ECM is controlling spark.

• | The engine coolant temperature (ECT) sensor is more than 60°C (140°F).

• | The engine speed is more than 2,000 RPM and steady.

• | The volumetric efficiency is steady.

• | DTCs P0327, P0328, P0332 and P0333 run continuously once the above conditions are met for approximately 20 seconds.

### Conditions for Setting the DTCs

#### DTCs P0324

The ECM detects an incorrect response to an internal ECM/KS circuitry test.

#### DTCs P0327 or P0332

The ECM detects a KS signal voltage that is less than the typical engine noise level for at least 4 seconds.

#### DTCs P0328 or P0333

The ECM detects the KS signal voltage is more than the maximum normal engine noise level for more than 4 seconds.

### Action Taken When the DTC Sets

DTCs P0324, P0327, P0328, P0332 and P0333 are type C DTCs.

### Conditions for Clearing the DTC

DTCs P0324, P0327, P0328, P0332 and P0333 are type C 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 correct 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.

• | The normal KS signal voltage is 0.25 volts when the KS is disconnected.

### 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 Verification

1. Start the engine. Observe the DTC information with a scan tool. DTCs P03247, P0327, P0328, P0332 or P0333 should not set.
2. If the vehicle passes the Circuit/System Verification Test then operate the vehicle within the conditions for running the DTC. You may also operate the vehicle within the conditions that are captured in the Freeze Frame/Failure Records List.

### Circuit/System Testing

1. Ignition OFF, disconnect the harness connector of the appropriate KS.
2. Ignition ON, connect a test lamp between the signal circuit of the KS and the a known groundl.

⇒ | If the test lamp illuminates, test the signal circuit for a short to voltage. If the circuits/connections test normal, replace the ECM.

3. Ignition ON, connect a test lamp between the signal circuit of the KS and B+l.

⇒ | If the test lamp illuminates, test the signal circuit for a short to ground. If the circuits/connections test normal, replace the ECM.

4. Ignition OFF, measure for less than1 ohms of resistance between the low reference circuit of the KS sensor harness side and a known ground.

⇒ | If the resistance is above the specified value, test the low reference circuit for an open/high resistance. If the circuits/connections test normal, replace the ECM.

5. If all circuits/connections test normal, replace the KS sensor.

### Repair Instructions

Perform the Diagnostic Repair Verification.

• | Knock Sensor Replacement - Bank 1

• | Knock Sensor Replacement - Bank 2

• | Engine Control Module Replacement for engine control module replacement, setup and programming.