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Home >> Chevrolet >> 2004 >> Optra Base, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - 1.6L (L91) - DTC P0107 To DTC P0335 >> DTC P0327 >> Test Description
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Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. 4:  This step tests for a short to voltage in the signal circuit of the KS.
  2. 5:  This step tests for a short to ground in the signal circuit of the KS.
  3. 6:  This step tests for an open or high resistance in the signal circuit or low reference circuit of the KS.
  4. 7:  This step tests for an open or high resistance in the low reference of the KS.
  5. 8:  This step tests for an open or high resistance in the shielded ground circuit of the KS.
Step Action Values Yes No
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Control Module Connector End Views or Engine Controls Connector End Views
1 Did you perform the Diagnostic System Check - Engine Controls? - Go to Step 2  Go to Diagnostic System Check - Engine Controls
2
IMPORTANT: If an engine mechanical noise can be heard, repair the condition before proceeding with this diagnostic. Refer to Symptoms - Engine Mechanical .
  1. Start the engine.
  2. Operate the engine within the Conditions for Running the DTC.
  3. Observe the DTC information with a scan tool.
Did DTC P0327 fail this ignition?		 - Go to Step 4  Go to Step 3 
3
  1. Observe the Freeze Frame/Failure Records for this DTC.
  2. Turn the ignition OFF for 30 seconds.
  3. Start the engine.
  4. 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.
Did the DTC fail this ignition?		 - Go to Step 4  Go to Diagnostic Aids
4 
  1. Turn OFF the ignition.
  2. Disconnect the knock sensor (KS) harness connector.
  3. Turn ON the ignition, with the engine OFF.
  4. Connect a test lamp from the signal circuit of the KS to a good ground.
Does the test lamp illuminate?		 - Go to Step 9  Go to Step 5 
5  Connect a test lamp from the signal circuit of the KS to the B+ terminal of the battery.
Does the test lamp illuminate?		 - Go to Step 9  Go to Step 6 
6 
  1. Turn OFF the ignition.
  2. Measure the resistance from the signal circuit to the low reference circuit of the KS on the controller side of the KS harness connector with the DMM.
Is the resistance within the specified range?		 96K-107K Ω Go to Step 8  Go to Step 7 
7  Measure the resistance from the low reference circuit of the KS on the controller side of the KS harness connector to a good ground with the DMM.
Is the resistance less than the specified value?		 5 Ω Go to Step 9  Go to Step 10 
8  Measure the resistance from the shielded ground circuit on the controller side of the KS harness connector to a good ground with the DMM.
Is the resistance less than the specified value?		 5 Ω Go to Step 12  Go to Step 11 
9 Test the signal circuit of the KS for one of the following conditions:
  • An open
  • A short to ground
  • A short to voltage
  • High resistance
  • A short between both circuits

Refer to Testing for a Short to Voltage and Wiring Repairs .
Did you find and correct the condition?		 - Go to Step 16  Go to Step 13 
10 Test the low reference circuit of the KS for one of the following conditions:
  • An open
  • High resistance

Refer to Testing for a Short to Voltage and Wiring Repairs .
Did you find and correct the condition?		 - Go to Step 16  Go to Step 13 
11 Test the shielded ground circuit of the KS for the following conditions:
  • An open
  • A high resistance

Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?		 - Go to Step 16  Go to Step 13 
12 Test for an intermittent and for a poor connection at the KS. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .
Did you find and correct the condition?		 - Go to Step 16  Go to Step 14 
13 Test for an intermittent and for a poor connection at the ECM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .
Did you find and correct the condition?		 - Go to Step 16  Go to Step 15 
14 Replace the KS. Refer to Knock Sensor Replacement .
Did you complete the replacement?		 - Go to Step 16  -
15 Replace the ECM. Refer to Engine Control Module Replacement .
Did you complete the replacement?		 - Go to Step 16  -
16
  1. Clear the DTCs with a scan tool.
  2. Turn OFF the ignition for 30 seconds.
  3. Start the engine.
  4. 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.
Did the DTC fail this ignition?		 - Go to Step 2  Go to Step 17 
17 Observe the Capture Info with a scan tool.
Are there any DTCs that have not been diagnosed?		 - Go to Diagnostic Trouble Code (DTC) List System OK
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