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Home >> Buick >> 2007 >> Allure CXS >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System & Fuel System - 3.6L - DTC P0008 To P0133 >> DTC P0112 >> 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 that a condition exists. If the temperature is more than the specified value, test for a condition in the circuits of the IAT sensor.
  2. 4:  This step isolates the condition. If the temperature is less than the specified value, the ECM and the signal circuit of the IAT sensor are OK.
DTC P0112

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 in Vehicle DTC Information
2 
  1. Turn ON the ignition, with the engine OFF.
  2. Observe the IAT sensor parameter with a scan tool.
Is the temperature more than the specified value?		 132°C (270°F) Go to Step 4  Go to Step 3 
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. Disconnect the mass air flow (MAF)/intake air temperature (IAT) sensor. Refer to Mass Airflow Sensor/Intake Air Temperature Sensor Replacement .
  2. Turn ON the ignition, with the engine OFF.
  3. Observe the IAT sensor parameter with a scan tool.
Is the temperature less than the specified value?		 -38°C (-36°F) Go to Step 6  Go to Step 5 
5
  1. Turn OFF the ignition.
  2. Disconnect the engine control module (ECM).
  3. Test the signal circuit of the IAT sensor 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 8  Go to Step 7 
6 Replace the IAT sensor. Refer to Mass Airflow Sensor/Intake Air Temperature Sensor Replacement .
Did you complete the replacement?		 - Go to Step 8  -
7 Replace the ECM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.
Did you complete the replacement?		 - Go to Step 8  -
8
  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 9 
9 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 in Vehicle DTC Information System OK
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