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Home >> Chevrolet >> 2002 >> Blazer 4D Utility, 4WD, Part Time >> Repair and Diagnosis >> External Pages >> Different car >> Section 1870 (Engine Controls And Fuel - 3.5L (L66) - DTC P2227 To DTC P2649) >> DTC P2271 or P2273 >> Test Description

Test Description

WARNING: This page is about a different car, the 2007 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.

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

  1. 2:  This step determines if an active malfunction exists.
  2. 6:  This step is testing for a rich fueling condition or the cause of a higher than normal sensor voltage.
DTC P2271 or P2273

Step Action Values Yes No
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Powertrain Control Module 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
2 
IMPORTANT:
  • DTC P2271 is for bank 1 sensor 2 and DTC P2273 is for bank 2 sensor 2.
  • Inspect the heated oxygen sensor (HO2S) 2 for being secure before proceeding with this DTC. A sensor that is loose could cause this DTC to set.
  1. Allow the engine to reach operating temperature.
  2. Operate the engine above 1,200 RPM for 2 minutes.
  3. Observe the appropriate HO2S 2 voltage parameter with a scan tool for 30 seconds.
Did the voltage drop to less than the specified value at least once?		 293 mV Go to Step 3  Go to Step 4 
3
  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 DTC P2271 or DTC P2273 fail this ignition?		 - Go to Step 4  Go to Intermittent Conditions
4
  1. Turn OFF the ignition.
  2. Disconnect the appropriate HO2S 2.
  3. Turn ON the ignition, with the engine OFF.
  4. Measure the voltage between the HO2S 2 signal circuit and a good ground with a DMM.
Is the voltage more than the specified value?		 1,050 mV Go to Step 5  Go to Step 6 
5 Test the appropriate HO2S 2 signal circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?		 - Go to Step 12  Go to Step 9 
6  Inspect for the following conditions:
  • For water intrusion in the HO2S harness connector
  • The HO2S is securely installed
  • Inspect for a collapsed air intake duct.
  • Inspect for a restricted air filter element. Refer to Air Cleaner Element Replacement .
  • Inspect the manifold absolute pressure (MAP) sensor for proper operation. Refer to Scan Tool Data List .
  • Inspect for excessive fuel in the crankcase. Change the oil as necessary.
  • Inspect for contaminated fuel. Refer to Alcohol/Contaminants-in-Fuel Diagnosis .
  • Inspect the engine control grounds for being clean, tight, and in the correct locations.
  • For the correct operation of the exhaust gas recirculation (EGR) valve.

Did you find and correct the condition?		 - Go to Step 12  Go to Step 7 
7
IMPORTANT: When you have completed the fuel system diagnosis, return to this diagnostic.
Test the fuel system for operating rich. Refer to Fuel System Diagnosis .Did you find and correct the condition?		 - Go to Step 12  Go to Step 8 
8 Test shorted terminals and for poor connections at the HO2S. Refer to Testing for Intermittent Conditions and Poor Connections and Wiring Repairs .
Did you find and correct the condition?		 - Go to Step 12  Go to Step 10 
9 Test shorted terminals and for poor connections at the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Wiring Repairs .
Did you find and correct the condition?		 - Go to Step 12  Go to Step 11 
10 Replace the appropriate HO2S. Refer to the appropriate procedure:
Did you complete the replacement?		 - Go to Step 12  -
11
  1. Replace the PCM. Refer to Control Module References for replacement, setup, and programming.
  2. Perform the idle learn procedure. Refer to Idle Learn .
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 - Vehicle System OK
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