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Home >> Buick >> 2004 >> Century Custom >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls (DTC P0030 To P0138) >> Engine Controls Diagnosis >> DTC P0101 >> Test Description
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Test Description

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

  1. 5:  This step will determine if the MAP sensor pressure is within the proper range for a given altitude.
  2. 6:  This step will determine if the MAP sensor voltage is within the proper range at idle.
  3. 7:  This step will determine if the MAP sensor responds properly to the change in manifold pressure.
  4. 8:  This step will determine if the TP sensor is operating properly.
  5. 9:  This step will determine if any mechanical faults have caused this DTC to set.
DTC P0101

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  Go to Diagnostic System Check - Engine Controls
2 Attempt to start the engine.
Does the engine start?		 - Go to Step 3  Go to Step 5 
3 Observe the Diagnostic Trouble Code (DTC) Information with the scan tool.
Does the scan tool display any other DTCs set?		 - Go to Diagnostic Trouble Code (DTC) List 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 Diagnostic Aids
5 
IMPORTANT: The Altitude vs. Barometric Pressure table indicates a pressure range for a given altitude under normal weather conditions. Weather conditions consisting of very low or very high pressure and/or temperature may cause a reading to be slightly out of range.
  1. Turn ON the ignition, with the engine OFF.
  2. Observe the MAP sensor kPa parameter with a scan tool.
  3. The manifold absolute pressure (MAP) sensor pressure should be within the specified range for your altitude. Refer to Altitude vs Barometric Pressure .
Is the MAP sensor pressure within the specified range as indicated on the Altitude vs Barometric Pressure table?		 - Go to Step 6  Go to Manifold Absolute Pressure (MAP) Sensor Diagnosis
6 
  1. Start the engine.
  2. Turn OFF all accessories.
  3. Allow the engine to reach operating temperature.
  4. Observe the MAP sensor parameter with a scan tool.
Is the MAP sensor parameter within the specified range?		 0.8-2.0 V Go to Step 7  Go to Manifold Absolute Pressure (MAP) Sensor Diagnosis
7 
  1. Idle the engine.
  2. Observe the MAP sensor parameter with a scan tool.
  3. Increase the engine speed slowly to 3,000 RPM and then back to idle.
Does the MAP sensor parameter change smoothly and gradually through the specified range of the test?		 - Go to Step 8  Go to Manifold Absolute Pressure (MAP) Sensor Diagnosis
8 
  1. Turn OFF the ignition for 30 seconds.
  2. Turn ON the ignition, with the engine OFF.
  3. Observe the TP sensor parameter at closed throttle with a scan tool.
  4. Depress the accelerator pedal completely.
  5. Observe the TP sensor parameter at wide open throttle with a scan tool.
Does the TP sensor parameter change from the first value to the second value?		 0-100% Go to Step 9  Go to DTC P0121 
9 
  1. Turn OFF the ignition.
  2. Inspect for the following conditions:
    • A restricted or collapsed air intake duct
    • A misaligned air intake duct
    • A dirty or deteriorating air filter element
    • Any objects blocking the air inlet screen of the mass air flow (MAF) sensor
    • Any contamination or debris on the sensing elements of the MAF sensor
    • Any water intrusion in the induction system
    • Any vacuum leak downstream of the MAF sensor
    • A skewed or stuck engine coolant temperature (ECT) sensor
    • Any type of restriction in the exhaust system-Refer to Restricted Exhaust in Engine Exhaust.
Did you find and correct the condition?		 - Go to Step 14  Go to Step 10 
10
  1. Disconnect the harness connector of the MAF sensor.
  2. Turn ON the ignition, with the engine OFF.
  3. Connect a test lamp between the ignition 1 voltage circuit of the MAF sensor and a good ground. Refer to Circuit Testing in Wiring Systems.
  4. Connect a DMM to the probe of the test lamp and a good ground. Refer to Measuring Voltage Drop in Wiring Systems.
Is the voltage within 0.50 volts of the specified value?		 B+ Go to Step 11  Go to Step 12 
11 Test for an intermittent and for a poor connection at the MAF 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 14  Go to Step 13 
12 Repair the high resistance in the ignition 1 voltage circuit of the MAF sensor. Refer to Wiring Repairs in Wiring Systems.
Did you complete the repair?		 - Go to Step 14  -
13 Replace the MAF sensor. Refer to Mass Air Flow (MAF) Sensor Replacement .
Did you complete the replacement?		 - Go to Step 14  -
14
  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 15 
15 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
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