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 DTC P0121, P0122, P0123, P0222, P0223, P0562, P0621, P0622, or P2135 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 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
- Clear the DTCs with a scan tool.
- Ignition OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down.
- Ignition ON.
- Verify the scan tool TAC Motor parameter displays Enabled while slowly depressing the accelerator pedal.
- If Enabled is not displayed
Refer to Circuit/System Testing.
- Go to next step: If Enabled is displayed
- If Enabled is not displayed
- Verify DTC P1516, P2101, P2119, or P2176 is not set.
- If any of the DTCs are set
Refer to Circuit/System Testing.
- Go to next step: If none of the DTCs are set
- If any of the DTCs are set
- Verify the scan tool TAC Motor parameter displays Enabled while performing the Throttle Sweep Test with a scan tool.
- If Enabled is not displayed
Replace the Q38 Throttle Body.
- Go to next step: If Enabled is displayed
- If Enabled is not displayed
- 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.
NOTE:
A low battery voltage or charging system condition may cause a DTC to set.
NOTE:
If there is a condition with the throttle body, the TAC Motor Command parameter will go to 99 % for a predetermined amount of time and then a DTC sets. Once a DTC is set, the TAC Motor Command parameter will go to 0 % and the TAC Motor parameter will display Disabled.