Cruze

DTC P0325

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 a 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 an 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. The circuits between the knock sensor and the ECM consist of the following circuits:

The ECM detects an incorrect knock sensor signal for greater than 4 s.

DTC P0324 00 is a Type C DTCs.

DTC P0324 00 is a Type C DTCs.

Schematic Reference

Engine Controls Schematics

Description and Operation

Knock Sensor System Description

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References

1. Engine running, observe the DTC information with a scan tool. DTC P0325 00 should not set.
2. 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: If the B68 Knock Sensor lead is damaged in any way, replace the B68 Knock Sensor.

1. Ignition OFF, disconnect the harness connector at the B68 Knock Sensor.
2. Ignition ON, test for 2-3 V between the low reference circuit terminal 2 and ground.

⇒	If less than the specified range, test the low reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module.

⇒	If greater than the specified range, test the low reference circuit for a short to voltage. If the circuit tests normal, replace the K20 Engine Control Module.

3. Ignition ON, test for 2-3 V between the signal circuit terminal 1 and ground.

⇒	If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 Engine Control Module.

⇒	If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K20 Engine Control Module.

4. If all circuits test normal, test or replace the B68 Knock Sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.