Action Taken When the DTC Sets

WARNING: This page is about a different car, the 2008 Buick LaCrosse and 2008 Buick Allure. However, it is still accessible from the selected car via links, so may be relevant.

DTC P1258 is a Type A DTC.
The engine will operate in the Overheated Engine Protection Operating Mode.
The engine coolant temperature indicator lamp, if equipped, will illuminate.
The driver information center (DIC), if equipped, may display a message.