Circuit Description
The control module contains a removable knock sensor (KS) module which receives the knock sensor input. The knock sensor signal input is filtered by this module before it is input to the controls module. Spark knock is continuously monitored during engine operation. If knock occurs for longer than a calibrated time, this diagnostic trouble code (DTC) will set.
Conditions for Running the DTC
| • | DTC P0327 is not active |
| • | The engine run time is 120 seconds or greater |
| • | The system voltage is between 10-17.1 volts |
Conditions for Setting the DTC
The VCM detects engine knock for more than 5 seconds.
Action Taken When DTC Sets
| • | The VCM will not illuminate the MIL |
| • | The VCM will store the conditions which were present when the DTC set as a Fail Records data only. This information will not store as Freeze Frame Data. |
| • | The VCM will use a calculated spark retard value in order to minimize the knock during the conditions when the knock is most likely to occur. The calculated value will vary based on the engine speed and load. |
Conditions for Clearing the MIL or DTC
| • | The control module turns OFF the MIL after 3 consecutive drive trips when the test has run and passed. |
| • | A history DTC will clear if no fault conditions have been detected for 40 warm-up cycles. A warm-up cycle occurs when the coolant temperature has risen 22°C (40°F) from the startup coolant temperature and the engine coolant reaches a temperature that is more than 70°C (158°F) during the same ignition cycle. |
| • | Use a scan tool in order to clear the DTCs. |
Diagnostic Aids
Check for the following conditions:
| • | A poor connection at the VCM. Inspect the KS module connector for the following conditions: |
| - | Backed out terminals |
| - | Broken locks |
| - | Improperly formed or damaged terminals |
| • | A damaged or improperly installed KS module. Check for the following items: |
| - | Bent pins |
| - | Deformed terminals |
| - | KS module not completely seated |
| • | Improper Knock Sensor torque specification. Torque the Knock sensor
to 19 N·m (14 lb ft). Refer to
Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems. in Cautions and Notices. |
Review the Fail Records vehicle mileage since the diagnostic test last failed in order to help determine how often the conditions that caused the DTC to set occur. This may assist in diagnosing the condition.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
This step ensures that the fault is present.
-
This step checks for an improperly installed Knock Sensor or poor connections.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 |
Important: Before clearing the DTCs, use the scan tool in order to record the Freeze Frame and the Failure Records for reference. This data will be lost when the Clear DTC Information function is used. Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | ||
|
Important: If you can hear the engine knock, repair the engine mechanical problem before proceeding with this diagnostic.
Does the scan tool indicate the DTC P0325 Failed This Ign? | -- | |||
3 |
Does the scan tool indicate DTC P0325 test Failed This Ign? | -- | Go to The Diagnostic Aids | |
4 |
Was a problem found? | -- | ||
Was a problem found? | -- | |||
6 |
Does the scan tool indicate the DTC P0325 Failed This Ign? | -- | ||
7 |
Is the action complete? | -- | -- | |
8 |
Does the scan tool indicate that this diagnostic ran and passed? | -- | ||
9 | Use the scan tool in order to display the Capture Info and the Review Capture Info functions. Are there any DTCs displayed that have not been diagnosed? | -- | Go to The Applicable DTC Table | System OK |
