P0325
DTC P0324, P0325, P0326, P0327, P0328, P0330, P0332, or P0333
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructionsprovides an overview of each diagnostic category.
DTC Descriptors
DTC P0324
- Knock Sensor (KS) Module Performance
DTC P0325
- Knock Sensor (KS) Circuit Bank 1
DTC P0326
- Knock Sensor (KS) Performance
DTC P0327
- Knock Sensor (KS) Circuit Low Voltage Bank 1
DTC P0328
- Knock Sensor (KS) Circuit High Voltage Bank 1
DTC P0330
- Knock Sensor (KS) Circuit Bank 2
DTC P0332
- Knock Sensor (KS) Circuit Low Voltage Bank 2
DTC P0333
- Knock Sensor (KS) Circuit High Voltage Bank 2
Diagnostic Fault Information
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 receives the KS signal through 2 isolated signal circuits for each KS. The ECM adjusts the spark timing based on the amplitude and frequency of each KS signal. The ECM learns a minimum noise level for each sensor at idle speeds, and uses calibrated noise level values for the rest of the RPM range. The ECM should monitor a normal KS signal within the noise channel.
Conditions for Running the DTC
P0324
* DTC P0325, P0326, P0327, P0328, P0330, P0332, or P0333 are not set.
* The engine speed is at least 400 RPM.
* DTC P0324 runs continuously when the above conditions are met.
P0325 or P0330
* DTC P0324, P0326, P0327, P0328, P0330, or P0332 are not set.
* The engine speed is at least 400 RPM.
* The engine coolant temperature (ECT) is warmer than -40°C (-40°F).
* The engine run time is at least 2 s.
* The power take-off (PTO) is not active.
* DTCs P0325 and P0330 run continuously when the above conditions are met.
P0326
* DTC P0068, P0120, P0122, P0123, P0220, P0222, P0223, P1516, P2135, or P2176 are not set.
* The engine speed is at least 400 RPM.
* The MAP is at least 10 kPa.
* DTC P0324 runs continuously when the above conditions are met.
P0327, P0328, P0332, and P0333
* The engine coolant temperature (ECT) is warmer than -40°C (-40°F).
* The engine run time is at least 2 s.
* DTCs P0327, P0328, P0332, and P0333 run continuously when the above conditions are met.
Conditions for Setting the DTC
P0324
The ECM has detected an internal circuitry fault for greater than 5 s.
P0325 and P0330
The KS signal circuits are open or shorted together for greater than 5 s.
P0326
* The KS signal indicates an engine knock is present.
* The ECM has commanded the spark retard to a value, which is more than the calibrated value, for a specific engine load and speed.
* The above conditions exist for more greater than 5 s.
P0327, P0328, P0332, and P0333
* The KS signal circuits are shorted to voltage or ground.
* The above conditions exist for greater than 5 s.
Action Taken When the DTC Sets
* DTCs P0324, P0325, P0326, P0327, P0328, P0330, P0332, and P0333 are Type B codes.
* The ignition timing is retarded to reduce the potential of engine damaging spark knock.
Conditions for Clearing the DTC
DTCs P0324, P0325, P0326, P0327, P0328, P0330, P0332, and P0333 are Type B codes.
Diagnostic Aids
* Inspect the KS for physical damage. A KS that is dropped or damaged may cause a DTC to set.
* Inspect the KS for proper installation. A KS that is loose or over torqued may cause a DTC to set. Refer to Fastener Tightening Specifications [1][2]Specifications.
* The KS mounting surface should be free of burrs, casting flash, and foreign material.
* The KS must be clear of hoses, brackets, and engine electrical wiring.
Reference Information
Schematic Reference
Engine Controls Schematics [1][2]Electrical Diagrams
Connector End View Reference
Component Connector End Views Connector End Views By Name
Description and Operation
Electronic Ignition System Description Electronic Ignition System Description
Electrical Information Reference
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Circuit Testing Circuit Testing
* Wiring Repairs Wiring Repairs
* Connector Repairs Connector Repairs
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References Programming and Relearningfor scan tool information
Special Tools
* J 35616 GM Approved Terminal Test Kit
* For equivalent regional tools, refer to Special Tools Tools and Equipment.
Circuit/System Verification
1. Engine idling at operating temperature, observe the DTC information with a scan tool. DTC P0324, P0325, P0326, P0327, P0328, P0330, P0332, or P0333 should not set.
2. Move the related harnesses and connectors for the knock sensor circuits while observing the scan tool parameters listed below. The parameters should say NO.
* Knock Detected Cyl. 1
* Knock Detected Cyl. 2
* Knock Detected Cyl. 3
* Knock Detected Cyl. 4
* Knock Detected Cyl. 5
* Knock Detected Cyl. 6
* Knock Detected Cyl. 7
* Knock Detected Cyl. 8
• If the parameters change, repair the wiring or the harness connectors.
3. Observe the DTC information with a scan tool. DTC P0324, P0325, P0326, P0327, P0328, P0330, P0332, or P0333 should not set.
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.
Circuit/System Testing
Note:
* You must perform the Circuit/System Verification first.
* If an engine mechanical noise can be heard, repair the condition before proceeding with this diagnostic. Refer to Symptoms - Engine Mechanical Symptoms - Engine Mechanical.
P0324
Note: If DTC P0325, P0326, P0327, P0328, P0330, P0332, or P0333 are also set, diagnose those DTCs first.
DTC P0324 indicates an internal control module circuitry failure. If no external knock sensor circuit issues exist, replace the ECM.
P0325, P0326, P0327, P0328, P0330, P0332, P0333
1. Verify the affected KS is properly tightened, refer to Fastener Tightening Specifications Fastener Tightening Specifications.
2. Ignition OFF, disconnect the affected KS.
3. Ignition OFF. Connect a DMM to both KS signal circuits, terminals A and B, at the affected KS. Set the DMM to the 400 mV AC scale, select the Hz mode. Let the reading stabilize at 0 Hz.
Note: DO NOT tap on plastic engine components.
4. Tap on the engine block with a non-metallic object near the KS and observe the DMM for a fluctuating frequency.
• If the DMM does not display a fluctuating frequency while tapping on the engine block then replace the KS.
5. Ignition OFF, with appropriate length jumper wires, connect the KS1 harness to the KS2 sensor and the KS2 harness to the KS1 sensor.
6. 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 KS.
7. Ignition OFF, remove the jumper wires from the previous step.
8. Measure for 2-3 volts between each of the following circuits and ground on the ECM side of the harness connector:
* The KS signal circuit, terminal A
* The KS signal circuit, terminal B
• 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 ECM.
• If greater than the specified range, test the circuits for a short to voltage. If the circuits test normal, replace the ECM.
9. Test for intermittent or poor connections at the ECM, KS, and in-line connectors where present.
10. If all circuits test normal, replace the ECM.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.
* Knock Sensor 1 Replacement Knock Sensor 1 Replacement
* Knock Sensor 2 Replacement Knock Sensor 2 Replacement
* Control Module References Programming and Relearningfor ECM replacement, setup, and programming