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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 P0113 >> 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 less than the specified value, test for a condition in the circuits of the IAT sensor.
  2. 5:  This step tests for high resistance in the low reference circuit of the MAF/IAT sensor. The MAF sensor and the IAT sensor share the low reference circuit. If there is a condition with the low reference circuit, a MAF and IAT sensor DTC may set. The ECM must be completely powered down to obtain an accurate resistance reading. It may take up to 30 minutes for the ECM to power down after the ignition key is removed. Removal of the ECM fuse, or the PCM/ETC fuse, allows the ECM to power down completely.
  3. 6:  This step tests the low reference circuit for a short to voltage. The control module or the sensor may be damaged if the circuit is shorted to battery voltage. Ensure that a short to voltage is repaired before replacing any components.
  4. 11:  Inspect the MAF/IAT sensor connector for water intrusion, corrosion, and bent or damaged terminals.
  5. 12:  Inspect the ECM connectors for water intrusion, corrosion, and bent or damaged terminals.
DTC P0113

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 less than the specified value?		 -38°C (-36°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. Turn OFF the ignition.
  2. Disconnect the mass air flow (MAF)/intake air temperature (IAT) sensor. Refer to Mass Airflow Sensor/Intake Air Temperature Sensor Replacement .
  3. Turn ON the ignition, with the engine OFF.
  4. Measure the voltage from the signal circuit of the IAT sensor to the engine control module (ECM) housing with a DMM.
Is the voltage within the specified range?		 4.8-5.2 V Go to Step 5  Go to Step 7 
5 
  1. Turn OFF the ignition.
  2. Remove the ECM fuse, or the PCM/ETC fuse, from the underhood electrical center.
    3. NOTE: Do NOT use a test lamp to test the continuity of the circuit. Damage to the control module may occur due to excessive current draw.
  3. Measure the resistance between the low reference circuit of the MAF/IAT sensor and the ECM housing with a DMM.
Is the resistance less than the specified value?		 5 Ω Go to Step 11  Go to Step 6 
6 
  1. Install the ECM fuse, or the PCM/ETC fuse, into the underhood electrical center.
  2. Turn ON the ignition, with the engine OFF.
  3. Measure the voltage between the low reference circuit of the MAF/IAT sensor and the ECM housing with a DMM.
Is the voltage less than the specified value?		 1.0 V Go to Step 10  Go to Step 13 
7 Is the voltage more than the specified value? 6 V Go to Step 8  Go to Step 9 
8
IMPORTANT: The control module or the sensor may be damaged if the circuit is shorted to battery positive voltage.
Test the signal circuit of the IAT sensor for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.Did you find and correct the condition?		 - Go to Step 16  Go to Step 12 
9 Test the signal circuit of the IAT sensor for an open, or for high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 16  Go to Step 12 
10 Test the low reference circuit of the MAF/IAT sensor for an open or a high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 16  Go to Step 12 
11  Test for shorted terminals and for poor connections at the MAF/IAT sensor. 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 16  Go to Step 14 
12  Test for shorted terminals and for poor connections at the 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 16  Go to Step 15 
13
IMPORTANT: The control module or the sensor may be damaged if the circuit is shorted to battery positive voltage.
Repair the short to voltage in the low reference circuit of the MAF/IAT sensor. Refer to Wiring Repairs in Wiring Systems.Did you complete the repair?		 - Go to Step 16  -
14 Replace the MAF/IAT sensor. Refer to Mass Airflow Sensor/Intake Air Temperature Sensor Replacement .
Did you complete the replacement?		 - Go to Step 16  -
15 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 16  -
16
  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 17 
17 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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