Circuit/System Verification

If there are other DTCs set besides DTC P2178, P2180, P2188, or P2190, refer to DIAGNOSTIC TROUBLE CODE (DTC) LIST - VEHICLE DIAGNOSTIC INFORMATION to diagnosis the applicable DTC.
Ignition ON, observe the scan tool 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 Total Fuel Trim Avg. parameter. The Total Fuel Trim Avg. should be between -22 to +23 percent.
- 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 percent 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/INTAKE AIR TEMPERATURE SENSOR REPLACEMENT .
  - Excessive fuel in the crankcase-Change the oil as necessary.
  - Fuel contamination-Refer to ALCOHOL/CONTAMINANTS-IN-FUEL DIAGNOSIS (W/O SPECIAL TOOL) or ALCOHOL/CONTAMINANTS-IN-FUEL DIAGNOSIS (W/ SPECIAL TOOL) .
  - The ECM grounds for being clean, tight, and in the correct locations
  - An engine mechanical condition-Refer to SYMPTOMS - ENGINE MECHANICAL .
  - Rich injectors-Refer to FUEL INJECTOR SOLENOID COIL TEST .
  - 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.