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

P0326 00

The control module detects an overactive knock sensor.

P06B6 00

The control module detects an internal circuitry fault.

DTCs P0326 00, and P06B6 00 are Type C DTCs.

DTCs P0326 00, and P06B6 00 are Type C DTCs.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Knock Sensor (KS) System Description

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Special Tools

For equivalent regional tools, refer to Special Tools.

1. Engine idling, observe the DTC information with a scan tool. Verify DTC P06B6 00 is not set.

⇒	If the DTC is set, replace the K20 Engine Control Module (ECM).

2. Ignition OFF, inspect for the following:

•	Inspect the B68 Knock Sensor for physical damage. A B68 Knock Sensor that is dropped or damaged may cause a DTC to set

•	Inspect the B68 Knock Sensor for proper installation. A B68 Knock Sensor that is loose or over torqued may cause a DTC to set. The B68 Knock Sensor should be free of thread sealant. The B68A Knock Sensor mounting surface should be free of burrs, casting flash, and foreign material

•	The B68A Knock Sensor 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 B68 Knock 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.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.