Circuit/System Verification
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 DTC P0641, P0651, P0697, P06A3 is not set.
- If any of the DTCs are set
Refer to: DTC P0641, P0651, P0697, or P06A3
- Go to next step: If none of the DTCs are set
- If any of the DTCs are set
- Verify the scan tool parameter: Throttle Body Idle Air Flow Compensation = Less than 90%
- If 90% or greater
Refer to: Throttle Body Cleaning
- Go to next step: If less than 90%
- If 90% or greater
- Perform the scan tool control function: Throttle Sweep - On
Verify the scan tool parameter: Throttle Position Sensors 1 and 2 = Agree
- If not the specified state
Refer to: DTC P0121-P0123, P0222, P0223, P16A0-P16A2, or P2135
- Go to next step: If the specified state
- If not the specified state
- Determine the current vehicle testing altitude.
- 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
- If not in the specified range
- Engine - Running
- Verify the scan tool parameter: MAP Sensor = 26 to 52 kPa (3. 8 to 7. 5 PSI) and changes - The value should change with accelerator pedal input.
- If not between 26 and 52 kPa (3. 8 and 7. 5 PSI) or does not change
Refer to: DTC P0106, P0107, or P0108
- Go to next step: If between 26 and 52 kPa (3. 8 and 7. 5 PSI) and changes
- If not between 26 and 52 kPa (3. 8 and 7. 5 PSI) or does not change
- Perform the following steps:
- Observe the scan tool parameter:
- MAF Sensor
- Engine Speed
- Increase the engine speed slowly to 3, 000 RPM and then back to idle.
- Review the scan tool snapshot data.
- Verify the scan tool parameter: MAF Sensor
The value should change smoothly and gradually as the engine speed is increased and decreased.
- If the value does not change smoothly and gradually
Refer to: DTC P0101-P0103
- Go to next step: If the value changes smoothly and gradually
- Observe the scan tool parameter:
- 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 that no DTCs are set.
- If any DTC is set
Refer to: Circuit/System Testing
- Go to next step: If no DTC is set
- If any DTC is set
- All OK.