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Home >> Saturn >> 2006 >> Ion Red Line >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - DTC P0132 To DTC P0340 >> DTC P0171 >> Test Description
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Test Description

The number below refers to the step number on the diagnostic table.

  1. 8:  If conditions were not corrected, a worn cam, worn intake or exhaust valves, or other engine mechanical failure may be at fault.
DTC P0171

Step Action Values Yes No
1 Did you perform the Diagnostic System Check - Vehicle? - Go to Step 2  Go to Diagnostic System Check - Vehicle
2 Are any DTCs other than DTC P0171 also set? - Go to Diagnostic Trouble Code (DTC) List - Vehicle Go to Step 3 
3
  1. Install a scan tool.
  2. Review the Freeze Frame/Failure Records and record the displayed data for this DTC.
  3. Select Fuel Trim Data parameter.
  4. Start the engine.
  5. Observe the Long Term FT parameter with a scan tool.
Is the Long Term FT parameter greater than the specified value?		 18% Go to Step 4  Go to Diagnostic Aids 
4
  1. Operate the engine at idle.
  2. Observe the Heated Oxygen Sensor (HO2S) parameters with a scan tool.
Does the scan tool indicate that the values are within the specified range and fluctuating?		 40-900 mV Go to Step 5  Go to Step 6 
5
  1. Turn OFF the engine.
  2. Visually and physically inspect the following items:
Did you find and correct the condition?		 - Go to Step 9  Go to Step 8 
6
  1. Turn OFF the engine.
  2. Turn ON the ignition, with the engine OFF.
  3. Observe the manifold absolute pressure (MAP) sensor pressure parameter with a scan tool. Refer to Altitude vs Barometric Pressure .
  4. The MAP sensor pressure should be within the range specified for your altitude.
Does the MAP indicate the correct barometric pressure?		 - Go to Step 7  Go to DTC P0106
7
  1. Turn OFF the engine.
  2. Inspect for the following conditions:
    • The HO2S for proper installation
    • Ensure that the electrical connectors and wires are secured and not contacting the exhaust system.
    • The HO2S signal circuit for an open or a short to ground-Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?		 - Go to Step 9  Go to Fuel System Diagnosis
8 
  1. Operate the engine at idle.
  2. Inspect for the following conditions:
    • Missing, loose, or leaking exhaust components
    • Vacuum leaks at the intake manifold, throttle body, and injector O-rings
    • The air induction system and air intake ducts for leaks
    • The crankcase ventilation system for leaks
    • The evaporative canister purge pipes for obstructions or plugging
Did you find and correct the condition?		 - Go to Step 9  Go to Symptoms - Engine Mechanical
9
IMPORTANT: After repairs, use the scan tool Fuel Trim Reset function in order to reset the Long Term Fuel Trim.
  1. Turn ON the ignition, with the engine OFF.
    2. IMPORTANT: Do not clear codes with the engine running. The codes may reset in the same ignition cycle.
  2. Clear the DTCs with a scan tool.
  3. Turn OFF the ignition for 30 seconds.
  4. Start the engine.
  5. 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 10 
10 Observe the Capture Info with a scan tool.
Have any other DTCs not been diagnosed?		 - Go to Diagnostic Trouble Code (DTC) List - Vehicle System OK
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