Circuit/System Verification

Observe the DTC information with a scan tool. DTC P2178, P2180, P2188, or P2190 should not be set.
- If any other DTC is set, refer to Diagnostic Trouble Code (DTC) List - Vehicle to diagnosis the applicable DTC.
Ignition ON, observe the barometric pressure (BARO) sensor pressure parameter and compare the reading on the scan tool to the barometric pressure table. Refer to Altitude Versus Barometric Pressure .
- If the BARO sensor pressure is not within the range specified for your altitude, refer to DTC P2227, P2228, or P2229 .
Engine at normal operating temperature, observe the scan tool Long Term Fuel Trim parameters. The LT FT Cruise/Accel parameters should be greater than -23 %. The LT FT Idle/Decel parameters should be greater than -7 %.
- If not within the specified range, inspect for the following conditions:
  - A mass air flow (MAF) sensor signal that is skewed. If the Short Term FT parameters for both banks changes greater than 20 % when the MAF sensor is disconnected, refer to DTC P0101 .
  - A collapsed air intake duct
  - A restricted air filter element-Refer to Air Cleaner Element Replacement .
  - The MAF sensor for foreign objects-Refer to Mass Airflow Sensor with Intake Air Temperature Sensor Replacement .
  - Excessive fuel in the crankcase-Change the oil as necessary.
  - Fuel contamination-Refer to Alcohol/Contaminants-in-Fuel Diagnosis (with Special Tool) or Alcohol/Contaminants-in-Fuel Diagnosis (w/o Special Tool) and Fuel System Cleaning .
  - The engine control module grounds for being clean, tight, and in the correct locations
  - Rich injectors-Refer to Fuel Injector Solenoid Coil Test (w/LLT) .
  - Restricted exhaust system-Refer to Symptoms - Engine Exhaust .
  - An engine mechanical condition-Refer to SYMPTOMS - ENGINE MECHANICAL .
Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.