1. Ignition OFF, disconnect the affected KS.
2. 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.
3. Tap on the engine block with a non-metallic object near the affected KS and observe the DMM for a fluctuating frequency.
锟斤拷If the DMM does not display a fluctuating frequency while tapping on the engine block then replace the affected KS.
4. Verify the affected KS is properly tightened, refer to Fastener Tightening Specifications (See: Engine, Cooling and
Exhaust/Engine/Specifications/Fastener Tightening Specifications).
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.
锟斤拷If the fault follows the sensor in question, replace the appropriate 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
锟斤拷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.
锟斤拷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 (See: Verification Tests) after completing the diagnostic procedure.
* Knock Sensor 1 Replacement (See: Powertrain Management/Computers and Control Systems/Knock Sensor/Service and Repair/Knock
Sensor 1 Replacement)
* Knock Sensor 2 Replacement (See: Powertrain Management/Computers and Control Systems/Knock Sensor/Service and Repair/Knock
Sensor 2 Replacement)
* Engine Control Module Replacement (See: Powertrain Management/Computers and Control Systems/Engine Control Module/Service and
Repair)
* Engine Control Module Programming and Setup (See: Powertrain Management/Computers and Control Systems/Engine Control
Module/Testing and Inspection)
P0333
DTC P0324, P0325, P0326, P0327, P0328, P0330, P0332, or P0333
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System
Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an
overview of the diagnostic approach.
* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure
Instructions) provides 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
CADILLAC Diagnostic and Repair Information ,Wiring Diagrams. DTC. TSB. Types: TSB, DTC, Wiring Diagrams, OEM Procedures. Trusted by more than 400,000 technicians. OEM accurate fix for faster repairs. Repair Procedures and Labor Times. Factory Auto Repair info. Request A Demo Today. Factory-Correct Diagrams. Factory Part Numbers. Maintenance Schedules. Repair Procedures. Labor Times. Types: TSB, DTC.