Conditions for Setting the DTC
WARNING: This page is about a different car, the 2007 Suzuki XL7. However, it is still accessible from the selected car via links, so may be relevant.
DTC P0851
The ECM detects "ON" signal from the Starter Inhibit Circuit while the TCM is commanding the Starter Inhibit Circuit "OFF" for 0.5 second.
DTC P0852
The ECM detects "OFF" signal from the Starter Inhibit Circuit while the TCM is commanding the Starter Inhibit Circuit "ON" for 0.5 second.