Circuit/System Testing

Allow the engine to reach operating temperature. With the engine running, observe the Long Term FT parameter with a scan tool. The reading should be between -20 and 0 percent.

• If not within the specified range, inspect for the following:

• With the engine idling and the transmission in the Park or Neutral position, observe the manifold absolute pressure (MAP) sensor parameter. The MAP sensor parameter should be between 19-42 kPa.
  • If the MAP sensor parameter is not between 19-42 kPa, refer to DTC P0106 or DTC P0107 or P0108 .
• With the engine idling, observe the mass air flow (MAF) sensor parameter. The MAF sensor parameter should be between 2-6 g/s at idle.
  • If the MAF sensor parameter is not between 2-6 g/s at idle, refer to DTC P0100-P0103 or DTC P0101 .
• Vacuum hoses for splits, kinks, and improper connections
• The air intake duct for being collapsed or restricted
• Leaks in the air induction system between the turbocharger outlet and the throttle body inlet, including the charge air cooler
• The air filter for being dirty or restricted
• Objects blocking the throttle body or MAF Sensor
• Excessive fuel in the crankcase due to leaking fuel injectors
• The evaporative emissions control system for improper operation
• Excessive fuel pressure-Refer to Fuel System Diagnosis .
• Malfunctioning fuel injectors
• Fuel contamination-Refer to Alcohol/Contaminants-in-Fuel Diagnosis .
• Missing, loose, or leaking exhaust components from the HO2S forward-Refer to Symptoms - Engine Exhaust .
• The HO2S for improper installation and for electrical wires or connectors that may have suffered corrosion, water intrusion, or contacted the exhaust system
• Incorrect terminal tension at electrical connectors
• Loose, corroded, or mislocated electrical ground connections
• A restricted exhaust system-Refer to Symptoms - Engine Exhaust .
• The HO2S signal circuit shorted to voltage
• Malfunctioning engine components-Refer to Symptoms - Engine Mechanical .