Circuit/System Verification

WARNING: This page is about a different car, the 2018 Chevrolet Suburban 3500 HD. However, it is still accessible from the selected car via links, so may be relevant.

Ignition ON.
Verify that DTC P0641, P0651, P0697 or P06A3 is not set.
- If any of the DTCs are set
  Refer to DTC P0641, P0651, P0697 or P06A3 (ECM) for further diagnosis.
- Go to next step: If none of the DTCs are set
Verify the scan tool Throttle Body Idle Air Flow Compensation parameter is less than 90%.
- 90% or greater
  Refer to Throttle Body Cleaning .
- Go to next step: If less than 90%
Verify the scan tool Throttle Position Sensors 1 and 2 Agree/Disagree parameter displays Agree while performing the Throttle Sweep Test with a scan tool.
- If Disagree
  Refer to DTC P0121-P0123, P0222, P0223, P16A0-P16A2 or P2135 for further diagnosis.
- Go to next step: If Agree
Determine the current vehicle testing altitude.
Verify the scan tool MAP Sensor pressure parameter is within the range specified in the Altitude Versus Barometric Pressure table.
- If the MAP Sensor parameter is not in range
  Refer to DTC P0106 for further diagnosis.
- Go to next step: If the MAP Sensor parameter is in range
Engine idling.
Verify the scan tool MAP Sensor parameter is between 26 - 52 kPa (3.8 - 7.5 PSI) and changes with accelerator pedal input.
- If the MAP Sensor parameter is not between 26 - 52 kPa (3.8 - 7.5 PSI) or does not change
  Refer to DTC P0106 for further diagnosis.
- Go to next step: If the MAP Sensor parameter is between 26 - 52 kPa (3.8 - 7.5 PSI) and changes
Verify the scan tool MAF Sensor g/s parameter changes smoothly and gradually as the engine speed is increased and decreased while performing the actions listed below.
1. Engine idling
2. Perform the scan tool snapshot function.
3. Increase the engine speed slowly to 3, 000 RPM and then back to idle.
4. Exit from the scan tool snapshot and review the data.
5. Observe the MAF Sensor parameter frame by frame with a scan tool.
- The MAF Sensor parameter does not change smoothly and gradually
  Refer to Circuit/System Testing below for further diagnosis.
- Go to next step: The MAF Sensor parameter changes smoothly and gradually
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 the DTC does not set.
- If the DTC sets
  Refer to Circuit/System Testing below for further diagnosis.
- Go to next step: If the DTC does not set
All OK