Conditions for Setting the DTC: P0852
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.
The ECM detects In Gear, the Park/Neutral switch signal equals 12 volts, High, when the IMS reports a Park/Neutral range for 3 seconds.