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. The KS should be free of thread sealant. 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.
For an intermittent condition, refer to Intermittent Conditions .

DTC P0327

Step	Action	Values	Yes	No
Schematic Reference: Engine Controls Schematics Connector End View Reference: Powertrain Control Module (PCM) Connector End Views or Engine Controls Connector End Views
1	Did you perform the Diagnostic System Check - Vehicle?	-	Go to Step 2	Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2	IMPORTANT: If an engine mechanical noise can be heard, repair the condition before proceeding with this diagnostic. Refer to Symptoms - Engine Mechanical in Engine Mechanical. Observe the Freeze Frame/Failure Records data for this DTC. Turn OFF the ignition for 30 seconds. Start the engine. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records. Does the DTC fail this ignition?	-	Go to Step 3	Go to Diagnostic Aids
3	Turn OFF the ignition. Disconnect the knock sensor (KS). Measure the resistance from the KS signal circuit on the sensor side of the KS harness connector to a good ground with the DMM. Measure the resistance from the KS low reference circuit on the sensor side of the KS harness connector to a good ground with the DMM. Does the DMM display an open for both circuits?	-	Go to Step 4	Go to Step 8
4	Connect the DMM from the KS signal circuit to the KS low reference circuit on the sensor side of the KS harness connector. Set the DMM to the 400 mV AC hertz scale and wait for the DMM to stabilize at 0 Hz. Refer to Measuring Frequency in Wiring Systems. IMPORTANT: Do not tap on plastic engine components. Tap on the engine block with a non-metallic object near the KS while observing the signal indicated on the DMM. Does the DMM display a fluctuating frequency while tapping on the engine block?	-	Go to Step 5	Go to Step 8
5	Turn ON the ignition, with the engine OFF. On the powertrain control module (PCM) side of the KS harness connector, measure the DC voltage from the KS signal circuit to a good ground with a DMM. On the PCM side of the KS harness connector, measure the DC voltage from the KS low reference circuit to a good ground with a DMM. Is the voltage more than the specified value on any circuit?	4.2 V	Go to Step 6	Go to Step 7
6	Turn OFF the ignition. Disconnect the PCM. Test the KS signal circuit or the KS low reference circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?	-	Go to Step 12	Go to Step 9
7	Turn OFF the ignition. Disconnect the PCM. Test the KS signal circuit and the KS low reference circuit for an open, for a high resistance, or for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?	-	Go to Step 12	Go to Step 9
8	Test for an intermittent and for a poor connection at the KS. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?	-	Go to Step 12	Go to Step 10
9	Test for an intermittent and for a poor connection at the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?	-	Go to Step 12	Go to Step 11
10	Replace the KS. Refer to Knock Sensor (KS) Replacement . Did you complete the replacement?	-	Go to Step 12	-
11	Replace the PCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement?	-	Go to Step 12	-
12	Clear the DTCs with a scan tool. Turn OFF the ignition for 30 seconds. Start the engine. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records. Does the DTC fail this ignition?	-	Go to Step 2	Go to Step 13
13	Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?	-	Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information	System OK