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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 P0131 >> 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 ground to the signal circuit of the O2S.
  2. 5:  This step tests the O2S signal and the low reference circuit for an open. The O2S voltage should go low.
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
  1. Start the engine.
  2. Allow the engine to reach the normal operating temperature.
  3. Operate the engine above 1,200 RPM for 30 seconds and then allow the engine to idle.
  4. Observe the Loop Status parameter with a scan tool.
Does the scan tool display Closed Loop?		 - Go to Step 3  Go to Step 4 
3
  1. Turn OFF the ignition for 30 seconds.
  2. Start the engine.
  3. Operate the vehicle within the Conditions for Running the DTC.
Does the DTC fail this ignition?		 - Go to Step 4  Go to Intermittent Conditions
4 
  1. Turn OFF the ignition.
  2. Disconnect the harness connector of the oxygen sensor (O2S).
  3. Turn ON the ignition, with the engine OFF.
  4. Observe the O2S voltage parameter with a scan tool.
Is the voltage within the specified range?		 350-550 mV Go to Step 5  Go to Step 8 
5 
  1. Connect a 5-amp fused jumper wire between the signal circuit and the low reference circuit of the O2S.
  2. Observe the O2S voltage parameter with a scan tool.
Is the voltage less than the specified value?		 20 mV Go to Step 7  Go to Step 6 
6
  1. Connect a 5-amp fused jumper wire between the O2S signal circuit and a good ground.
  2. Observe the O2S voltage parameter with a scan tool.
Is the voltage less than the specified value?		 20 mV Go to Step 9  Go to Step 8 
7 Test or inspect for the following conditions:
Did you find and correct the condition?		 - Go to Step 14  Go to Step 10 
8 Test the O2S signal circuit for one of the following conditions:
  • A short to ground
  • An open
  • High resistance

Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 14  Go to Step 11 
9 Test the O2S low reference circuit for one of the following conditions:
  • A short to voltage
  • An open
  • High resistance

Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 14  Go to Step 11 
10 Test for shorted terminals and poor connections at the O2S. 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 14  Go to Step 12 
11 Test for shorted terminals and poor connections at the engine control module (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 14  Go to Step 13 
12 Replace the O2S. Refer to Oxygen Sensor Replacement .
Did you complete the replacement?		 - Go to Step 14  -
13 Replace the ECM. Refer to Engine Control Module Replacement .
Did you complete the replacement?		 - Go to Step 14  -
14
  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.
Did the DTC fail this ignition?		 - Go to Step 2  Go to Step 15 
15 Are there any DTCs that have not been diagnosed? - Go to Diagnostic Trouble Code (DTC) List System OK
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