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Home >> Chevrolet >> 2004 >> Epica LS >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - 2.0L (L34 GMDAT) DTC P0141 To DTC P0700 >> DTC P0327 >> Test Description

Test Description

The number below refers to the step number on the diagnostic table.

  1. 2:  This step determines if the fault is current.
  1. 3:  This step determines if the fault is intermittent.
Step Action Values Yes No
Schematic Reference:  Engine Controls Schematics (European Emissions)  or  Engine Controls Schematics (Non-European Emissions) 
Connector End View Reference:  Engine Control Module (ECM) 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 (Non European Emissions) or Diagnostic System Check - Engine Controls (European Emissions)
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 - 2.0L (L34GMDAT).
  1. Start the engine.
  2. 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. Measure the resistance from the signal circuit and the low reference circuit on the controller side of the KS harness connector to a good ground with the DMM.
Is the resistance within the specified range?		 96K-107K Ω Go to Step 5  Go to Step 6 
5 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 within the specified range?		 92-98 Ω Go to Step 8  Go to Step 7 
6 Test the signal circuit and the low reference circuit on the controller side of the KS for 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 andWiring Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 12  Go to Step 9 
7 Test the shielded ground circuit on the controller side of the KS for the following conditions:
  • An open
  • A short to ground
  • A high resistance
  • 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 
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 ECM. 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 ECM. Refer to Engine Control Module (ECM) Replacement (Non European Emissions) or Engine Control Module (ECM) Replacement (European Emissions) .
Did you complete the replacement?		 - Go to Step 12  -
12
  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 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 System OK
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