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Home >> Buick >> 2007 >> Allure CXS >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System & Fuel System - 3.6L - DTC P2231 To P2626 >> DTC P2237 >> Test Description
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Test Description

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

  1. 2:  This step determines if the condition exists. The HO2S lambda parameter should react immediately to the changes in throttle position when performing this test.
  2. 4:  This step determines if there is a condition with the pumping current circuit. Connecting a jumper wire between the reference voltage and the low reference circuits causes the ECM to command the pumping current and the input pumping current circuits.
DTC P2237

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 - Vehicle? - Go to Step 2  Go to Diagnostic System Check - Vehicle
2 
  1. Start the engine.
  2. Allow the engine to reach operating temperature.
  3. Cycle the throttle from idle to wide open throttle 3 times within 5 seconds.
  4. Observe the HO2S 1 lambda parameter with a scan tool.
Does the HO2S lambda value react immediately to the above action?		 - 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 the DTC fail this ignition?		 - Go to Step 4  Go to Diagnostic Aids
4 
  1. Turn OFF the ignition.
  2. Disconnect the heated oxygen sensor (HO2S) 1.
  3. Turn ON the ignition, with the engine OFF.
  4. Connect a 3-amp fused jumper wire between the reference voltage circuit and the low reference circuit of the HO2S.
  5. Measure the voltage between the input pump current circuit and a good ground.
Is the voltage more than the specified value?		 1 V Go to Step 6  Go to Step 5 
5 Test the input pump current circuit of the HO2S for an open. Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?		 - Go to Step 10  Go to Step 7 
6 Test for an intermittent and for a poor connection at the HO2S. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .
Did you find and correct the condition?		 - Go to Step 10  Go to Step 8 
7 Test for an intermittent and for a poor connection at the engine control module (ECM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .
Did you find and correct the condition?		 - Go to Step 10  Go to Step 9 
8 Replace the HO2S. Refer to Heated Oxygen Sensor 1 Replacement .
Did you complete the replacement?		 - Go to Step 10  -
9 Replace the ECM. Refer to Control Module References for replacement, setup, and programming.
Did you complete the replacement?		 - Go to Step 10  -
10
  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 11 
11 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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