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
- Go to next step: If in the specified range
- Engine - Idling - At normal operating temperature
- Verify the scan tool parameter: Long Term Fuel Trim Bank 1, 2 = -10 to 10%
- If greater than 10%
- Ignition/Vehicle - Off
- 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 Injector - Malfunction - 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
- Vacuum leak @ Engine - Oil Level Indicator and Tube /Oil Filler Cap
- If a condition exists - Repair or replace as necessary
- If no condition exists - Refer to: Symptoms - Engine Mechanical
- If less than -10%
- Ignition/Vehicle - Off
- 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 Injector - Malfunction - 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
- If no condition exists - Refer to: Symptoms - Engine Mechanical
- 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, P0174, P0175 is not set.
- If the DTC sets
Repeat step 4
- Go to next step: If no DTC is set
- If the DTC sets
- All OK.