2009 Buick Lucerne - How serious?

Driving rather slow speed in our neighborhood when our car jerked and then the ABS litght came on. Note appeared indicating to service traction stability control.

What is happening and how serious is this?

You answered every question yourself.

How serious is it… the car jerked while you were driving it. That is pretty serious, I’d say.

Whay is happening… your car tells you to service the stability control. So take it to your favorite auto shop or the dealer to get the stability control serviced.