Captiva

DTC P0324-P0328, P0330-P0333, P06B6, or P06B7

The knock sensor 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 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 2 isolated signal circuits for each bank. The ECM learns a minimum knock sensor noise level at idle and uses calibrated values for the rest of the RPM range. The ECM monitors for a normal knock sensor signal. The ECM monitors the internal knock sensor processor by verifying a 20 KHz signal generated on the output circuit is detected on the return circuit.

P0324, P0326 and P0331--Excessive Knock Detection Mode

P0324, P0326 and P0331--Abnormal Noise Detection Mode--Improperly Bolted Knock Sensor

P0325, P0327, P0328, P0330, P0332, and P0333

P06B6 and P06B7

P0324

The ECM detects that the knock sensor signal indicates an excessive engine knock is present for greater than 10 s for at least 1 single cylinder.

P0325 and P0330

The ECM detects that the knock sensor signal circuits are open for greater than 10 s.

P0326 and P0331

P0327 and P0332

The ECM detects that the knock sensor signal circuits are shorted to ground for greater than 10 s.

P0328 and P0333

The ECM detects that the knock sensor signal circuits are shorted to voltage for greater than 10 s.

P06B6 and P06B7

The ECM has detected an internal knock sensor processor fault.

DTCs P0324, P0325, P0326, P0327, P0328, P0330, P0331, P0332 P0333, P06B6, and P06B7 are Type B DTCs.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Electronic Ignition 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

1. Engine at operating temperature, all accessories OFF, and engine speed greater than 2,000 RPM, observe the Knock Retard and Total Knock Retard parameters. The parameters should be 0°.
2. Engine idling, move the related harnesses and connectors for the knock sensor circuits while observing the scan tool Knock Retard and Total Knock Retard parameters. The parameters should remain steady with no abrupt changes.
3. 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.

Note: 

P0324, P0326 and P0331

1. Using a scan tool, verify DTCs P0335 or P0336 are not set.

⇒	If any of the DTCs are set, diagnose them first. Refer to Diagnostic Trouble Code (DTC) List - Vehicle .

2. Verify the following conditions do not exist.

•	A loose or broken vehicle accessory

•	A loose or broken accessory bracket

•	Excessive engine mechanical noise

⇒	If any of the conditions exist, repair as necessary.

3. Replace the K20 ECM if no external knock sensor circuit issues exist.

P0325, P0327, P0328, P0330, P0332, and P0333

1. Ignition OFF, disconnect the appropriate B68 knock sensor.
2. Verify the affected B68 knock sensor is properly tightened, refer to Fastener Tightening Specifications .
3. Ignition OFF, with appropriate length jumper wires, connect the B68A knock sensor 1 harness to the B68B knock sensor 2 sensor and the B68B knock sensor 2 harness to the B68A knock sensor 1 sensor.
4. Monitor the DTCs using a scan tool. Operate the vehicle within the conditions for running the DTC. Verify the fault does not follow the sensor in question.

⇒	If the fault follows the sensor in question, replace the appropriate B68 knock sensor.

5. Ignition OFF, remove the jumper wires from the previous step.
6. Ignition ON, measure for 1-4 V between each of the following circuits and ground on the K20 ECM side of the harness connector:

•	The B68 knock sensor signal circuit, terminal A or 1

•	The B68 knock sensor signal circuit, terminal B or 2

⇒	If less than the specified range, test the circuits for a short to ground or an open/high resistance. If the circuits test normal, replace the K20 ECM.

⇒	If greater than the specified range, test the circuits for a short to voltage. If the circuits test normal, replace the K20 ECM.

7. Test for intermittent or poor connections at the ECM, B68 knock sensor, and in-line connectors where present.
8. If all circuits test normal, replace the K20 ECM.

P06B6 or P06B7

1. Using a scan tool, verify the following DTCs are not set: P0325, P0327, P0328, P0330, P0332, and P0333.

⇒	If any of the DTCs are set, diagnose them first.

2. DTCs P06B6 and P06B7 indicate an internal ECM circuitry failure. Verify the external knock sensor circuits and connectors for proper condition.

⇒	If no external knock sensor circuit issues exist, replace the K20 ECM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.