Circuit/System Verification
WARNING: This page is about a different car, the 2019 Buick Cascada, 2018 Buick Cascada, and 2017 Buick Cascada. However, it is still accessible from the selected car via links, so may be relevant.
- Ignition ON,
- Verify that DTC P0601 - P0606, P06A3, or P16F3 is not set.
- If a DTC is set
Refer to Diagnostic Trouble Code (DTC) List - Vehicle for further diagnosis.
- Go to next step: If a DTC is not set
- If a DTC is set
- Verify the scan tool Throttle Body Idle Air flow Compensation parameter is less than 90 %.
- If 90 % or greater
Refer to Throttle Body Inspection and 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
Test or replace the Q38 Throttle Body.
- If any of the DTCs are set
Refer to Circuit/System Testing
- 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 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
Test or replace the Q38 Throttle Body Assembly.
- Go to next step: If Agree is displayed
- If Agree is not displayed
- Verify DTC P0121, P0122, P0123, P0222, P0223, P16A0, P16A1, P16A2, and P2135 is not set.
- If a DTC is set
Refer to Circuit/System Testing.
- Go to next step: If a DTC is not set
- If a DTC is 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 MAP Sensor pressure is not in range
Refer to DTC P0106 .
- Go to next step: If the MAP Sensor pressure is within range
- If the MAP Sensor 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 between 26 - 52 kPa (3.8 - 7.5 psi) or does not change
Refer to DTC P0106 .
- Go to next step: If between 26 - 52 kPa (3.8 - 7.5 psi) and changes
- If not between 26 - 52 kPa (3.8 - 7.5 psi) 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
- Verify the scan tool Boost Pressure Sensor pressure and BARO parameters are within 3 kPa (0.4 psi).
- If the parameters are not within 3 kPa (0.4 psi)
Refer to DTC P0236 .
- Go to next step: If the parameters are within 3 kPa (0.4 psi)
- If the parameters are not within 3 kPa (0.4 psi)
- Verify the scan tool MAP Sensor parameter and the Boost Pressure Sensor parameter are within 20 kPa (2.9 psi) during a WOT acceleration at the time of the 1 - 2 shift.
- If the parameters are not within 20 kPa (2.9 psi)
Refer to DTC P0236
- Go to next step: If the parameters are within 20 kPa (2.9 psi)
- If the parameters are not within 20 kPa (2.9 psi)
- 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.
- Go to next step: If the DTC does not set
- If the DTC sets
- All OK.