Conditions for Setting the DTC
WARNING: This page is about a different car, the 2017 GMC Yukon XL, 2017 GMC Yukon, 2017 Chevrolet Tahoe, 2017 Chevrolet Suburban 3500 HD, and 2017 Chevrolet Suburban. However, it is still accessible from the selected car via links, so may be relevant.
P0850 or P0851
The ECM detects the Park/Neutral switch signal equals 0 V, Low, when the IMS reports a Drive range.
P0852
The ECM detects the Park/Neutral switch signal equals 12 V, High, when the IMS reports a Park/Neutral range.