Diagnostic Aids
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.
If a short to ground exists on BCM terminal 5 X1, the amber LEDs on the park assist switch and lane departure warning switch may flash after the fault is repaired. Disconnect the negative battery cable for 30 s to clear the fault.