Circuit/System Verification
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2018 GMC Yukon XL, 2018 GMC Yukon, 2018 Chevrolet Tahoe, 2018 Chevrolet Suburban, and 2018 Cadillac Escalade ESV. However, it is still accessible from the selected car via links, so may be relevant.
- Ignition ON.
- If you were sent here from DTC P0068, P0101, P0106 or P1101 refer to Circuit/System Testing.
- Verify that DTC P0601 - P0606, P06A3 and P16F3 is not set.
- If any of the DTCs are set
Refer to Diagnostic Trouble Code (DTC) List - Vehicle for further diagnosis.
- Go to next step : If none of the DTCs are set
- If any of the DTCs are set
- Verify the scan tool Throttle Body Idle Airflow Compensation parameter is less than 90%.
- If 90% or greater
Refer to Throttle Body Cleaning .
- Go to next step : If less than 90%
- If 90% or greater
- Verify that DTC P0122, P0123, P0222, P0223, P16A0, P16A1, P16A2 or P2135 are not set.
- If DTC P0122, P0123, P0222, P0223 or P2135 are the only DTCs set
Replace the Q38 Throttle Body.
- If DTC P16A0, P16A1 or P16A2 is set with any of the DTCs
Refer to Circuit/System Testing below.
- Go to next step : If none of the DTCs are set
- If DTC P0122, P0123, P0222, P0223 or P2135 are the only DTCs set
- 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 Agree is not displayed
Replace the Q38 Throttle Body.
- Go to next step : If Agree is displayed
- If Agree is not displayed
- Verify DTC P0122, P0123, P0222, P0223, P16A0, P16A1, P16A2 or P2135 is not set.
- If any of the DTCs are set
Refer to Circuit/System Testing below.
- Go to next step : If none of the DTCs are set
- If any of the DTCs are set
- Determine the current vehicle testing altitude.
- Verify the scan tool MAP Sensor pressure parameter is within range specified in the Altitude Versus Barometric Pressure
table.
- If the pressure is not in range
Refer to DTC P0106 .
- Go to next step : If the pressure is within range
- If the pressure is not in range
- Engine idling.
- Verify the scan tool MAP Sensor pressure parameter is between 26 - 52 kPa (3.8 - 7.5 psi) and changes with accelerator pedal input.
- If not within the specified range or does not change
Refer to DTC P0106 .
- Go to next step : If within the specified range and changes
- If not within the specified range or does not change
- 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.
- Engine idling
- Perform the scan tool snapshot function.
- Increase the engine speed slowly to 3, 000 RPM and then back to idle.
- Exit from the scan tool snapshot and review the data.
- Observe the MAF Sensor parameter frame by frame with a scan tool.
- If the parameter does not change smoothly and gradually
Refer to DTC P0101 .
- Go to next step : If the 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.
- Go to next step : If the DTC does not set
- If the DTC sets
- All OK.