could be a number of things
how are the tires? could be going bald causing slip. Check front and rear tires
is it colder now than before? Tires could be harder due to lower temps, hence less grip
Could be alignment related, if your alignment is really off.
tire pressure? A leaking/low pressure tire, will show lower speed than the rest and going around the corner this could meet/exceed the abs/dsc treshold activating the system.