Circuit/System Testing
WARNING: This page is about a different car, the 2019 GMC Savana 3500, 2019 GMC Savana 2500, 2019 Chevrolet Express 3500, and 2019 Chevrolet Express 2500. However, it is still accessible from the selected car via links, so may be relevant.
- 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
- Go to next step: If in the specified range
- If not in the specified range
- Ignition/Vehicle - Off
- Verify a condition does not exist with the component: Blade @ Q38 Throttle Body
- Binding or Sticking @ Open/Close - Position
- Coking/Debris/Dirty/Ice/Visible Damage
- Open @ Engine Off
- Open/Close - Without spring pressure
- If a condition exists
Repair as necessary
- Go to next step: If no condition exists
- Engine - Idling - At normal operating temperature
- Verify the scan tool parameter: Long Term Fuel Trim = -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 Injectors - Restricted - Refer to: Fuel Injector Diagnosis
- Fuel Pressure Low - Refer to: Fuel System Diagnosis (Without FPCM) , or Fuel System Diagnosis (FPCM)
- 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 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 Injectors - Leaking - Refer to: Fuel System Diagnosis (Without FPCM) , or Fuel System Diagnosis (FPCM)
- Fuel Pressure - High - Refer to: Fuel System Diagnosis (Without FPCM) , or Fuel System Diagnosis (FPCM)
- 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.