Diagnostic Instructions

DTC Descriptors

DTC P0324: Knock Sensor Module Performance

DTC P0325: Knock Sensor 1 Circuit Malfunction (Bank 1)

DTC P0326: Knock Sensor 1 Circuit Range/Performance (Bank 1 Or Single Sensor)

DTC P0327: Knock Sensor Circuit Low Frequency (Bank 1)

DTC P0328: Knock Sensor Circuit High Frequency (Bank 1)

DTC P0330: Knock Sensor 2 Circuit Malfunction (Bank 2)

DTC P0332: Knock Sensor Circuit Low Frequency (Bank 2)

DTC P0333: Knock Sensor Circuit High Frequency (Bank 2)

Diagnostic Fault Information

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
Knock Sensor Signal	P0327, P0332, P0328, P0332	P0325, P0330	P0325, P0330	P0326, P0331
Low Reference	P0327, P0332, P0328, P0332	P0325, P0330	P0325, P0330	P0326, P0331

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 adjusts the spark timing based on the amplitude and frequency of each KS signal. The ECM receives the KS signal through 2 different signal circuits. Each KS ground is supplied by the ECM through a low reference circuit. The ECM uses the KS signal to calculate the average voltage then assign a voltage range value. The ECM will then monitor for a normal KS signal within the assigned voltage range.

Conditions for Running the DTC

Conditions for Setting the DTC

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

Action Taken when the DTC Sets

DTCs P0324, P0325, P0326, P0327, P0328, P0330, P0332 or P0333 are type B DTCs.

Conditions for Clearing the DTC

DTCs P0324, P0325, P0326, P0327, P0328, P0330, P0332 or P0333 are type B DTCs.

Diagnostic Aids

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

Scan Tool Reference

Control Module References

Circuit/System Verification

1. Disconnect both KS harness connection.
2. Connect one test lead from the DMM to the signal circuit terminal on the KS, and the other test lead form the DMM to the low reference circuit terminal on the KS.
3. Set the DMM to the 400 mV AC hertz scale and wait for the DMM to stabilize at 0 Hz.

Important: DO NOT tap on plastic engine components.

4. Tap on the engine block with a non-metallic object near the KS while observing the Hz signal indicated on the DMM display.
5. The DMM should display a fluctuating frequency while tapping on the engine block.
6. Repeat the above procedure for the KS on the opposite side of the engine block.

⇒

If the vehicle passes the Circuit/System Verification test, 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 data list. The other option is to refer to Testing for Intermittent Conditions and Poor Connections .

Circuit/System Testing

P0324

This DTC indicates a KS circuit failure internal to the ECM. Replace the Control Module.

P0325, P0327, P0328, P0330, P0332, P0333

1. Ignition OFF.
2. Disconnect the KS harness connection.
3. Measure for infinite resistance between the signal circuit terminal at the KS, and to a known ground with a DMM.

⇒	If continuity is detected on the signal circuit, replace the KS.

4. Measure for infinite resistance between the low reference circuit terminal at the KS and to a known ground with a DMM.

⇒	If continuity is detected on the low reference circuit, replace the KS.

5. Ignition ON, engine OFF.
6. Measure for voltage at the KS signal circuit terminal, on the wire harness connector, for the KS.

⇒	If the KS signal circuit measures more than 4.2 volts, test for a short to voltage. If the circuit tests normal, replace the ECM.

7. Measure for voltage at the KS low reference circuit terminal at the wire harness connector for the KS.

⇒	If the KS low reference circuit measures more than 4.2 volts, test for a short to voltage. If the circuit tests normal, replace the ECM.

8. Test the KS signal circuit and the KS low reference circuit for the following conditions:

•	An open circuit

•	A short to ground

•	High resistance--All wire circuit resistance must measure less than 5 ohms.

⇒	. If the circuit tests normal, replace the ECM.

P0326

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.