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Home >> Buick >> 2004 >> Century Base >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls (DTC P0030 To P0138) >> Engine Controls Diagnosis >> DTC P0137 >> Conditions for Clearing the MIL/DTC
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Conditions for Clearing the MIL/DTC

DTC P0137

Step Action Values Yes No
Schematic Reference:  Engine Controls Schematics 
Connector End View Reference:  Engine Controls Connector End Views  or  Powertrain Control Module (PCM) Connector End Views 
1 Did you perform the Diagnostic System Check-Engine Controls? - Go to Step 2  Diagnostic System Check - Engine Controls
2
  1. Start the engine.
  2. Allow the engine to idle at operating temperature. Refer to Scan Tool Data List .
  3. Clear the DTC and record the Freeze Frame/Failure Records.
  4. Observe the heated oxygen sensor (HO2S) 2 voltage parameter with a scan tool.
  5. Vary the engine speed from idle to 3,000 RPM several times within 5 seconds.
Is the HO2S 2 voltage less than the specified value?
30 mV Go to Step 5  Go to Step 3 
3 Is the HO2S 2 voltage within the specified range? 425-475 mV Go to Step 4 in DTC P0140 Go to Step 4 
4
  1. Observe the Freeze Frame/Failure Records for this DTC.
  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 5  Go to Intermittent Conditions
5
  1. Turn OFF the ignition.
  2. Disconnect the HO2S 2 connector.
  3. Connect a 3-amp fused jumper wire between the HO2S 2 low signal circuit, on the engine harness side, and a good ground.
  4. Turn ON the ignition, with the engine OFF.
  5. Observe the HO2S 2 voltage parameter with a scan tool.
Is the HO2S voltage less than the specified value?
30 mV Go to Step 6  Go to Step 7 
6 Test the HO2S 2 high signal circuit 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 
7 Inspect the following conditions that may affect the HO2S operation:
Did you find and correct the condition?
- Go to Step 12  Go to Step 8 
8 Test for an intermittent and for a poor connection at the HO2S 2 harness connector. 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 powertrain control module (PCM) harness connectors. 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 HO2S 2. Refer to Heated Oxygen Sensor Replacement - Position 2 .
Did you complete the replacement?
- Go to Step 12  -
11 Replace the PCM. Refer to Powertrain Control Module (PCM) Replacement .
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