Diagnostic Aids
WARNING: This page is about a different car, the 2020 Buick Regal and 2019 Buick Regal. However, it is still accessible from the selected car via links, so may be relevant.
- Review scan tool Cylinder Deactivation Disable History to determine reason for disabling cylinder deactivation.
- DTC P3400 may set if the PCV hose is disconnected from the inlet duct.