Circuit/System Testing

WARNING: This page is about a different variant/trim than selected.

Ignition - On/Vehicle - In Service Mode
Verify the scan tool parameter: MAP Sensor = Altitude Versus Barometric Pressure - The value should be within the range listed in the table:
- If not in the specified range
  Refer to: DTC P0106, P0107, or P0108
- Go to next step: If in the specified range
Engine - Idling - At normal operating temperature
Verify the scan tool parameter: Long Term Fuel Trim = -10 to 10%
- If greater than 10%
1. Ignition/Vehicle - Off
2. Verify the following conditions do not exist:
  - A cracked EVAP canister.
  - Air Cleaner Element - Missing
  - Exhaust System - Leaking/Missing components/Restricted - Refer to: Symptoms - Engine Exhaust
  - Fuel - Contaminated/Poor Quality - Refer to: Alcohol/Contaminants-in-Fuel Diagnosis
  - Fuel Injectors - Restricted - Refer to: Fuel Injector Diagnosis
  - Fuel Pressure Low - Refer to: Fuel System Diagnosis
  - Insufficient amount of fuel in the tank.
  - Intake Manifold - Leaking
  - Intake Air Duct - Loose Clamps/Cracked/Visible Damage
  - Mass Airflow Sensor - Contamination of the measuring element/Water intrusion
  - Positive Crankcase Ventilation System - Incorrect connection/Leaking/Restricted - Refer to: Crankcase Ventilation System Inspection/Diagnosis
  - Vacuum Hoses - Incorrect connection/Kinked/Leaking/Restricted
  - If a condition exists - Repair or replace as necessary
- If less than -10%
1. Ignition/Vehicle - Off
2. Verify the following conditions do not exist:
  - Air Cleaner Element - Dirty/Restricted/Saturated with water
  - Evaporative Emission (EVAP) System - Saturated with fuel/Missing components/Visible Damage
  - Exhaust System/Catalyst System - Leaking/Missing components/Restricted/Severe discoloration caused by excessive temperatures/Visible Damage - Refer to: Symptoms - Engine Exhaust
  - Fuel - Contaminated/Poor Quality - Refer to: Alcohol/Contaminants-in-Fuel Diagnosis
  - Fuel Injectors - Leaking - Refer to: Fuel Injector Diagnosis
  - Fuel Pressure - High - Refer to: Fuel System Diagnosis
  - Intake Air Duct - Collapsed/Visible Damage
  - MAF Sensor - Contamination of the measuring element
  - Positive Crankcase Ventilation System - Saturated with fuel - Refer to: Crankcase Ventilation System Inspection/Diagnosis
  - If a condition exists - Repair or replace as necessary
- Go to next step: If between -10 and 10%
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 data.
Verify DTC P0171, P0172 is not set.
- If the DTC sets
  Repeat step 4
- Go to next step: If no DTC is set
All OK.