Theory Of Operation
WARNING: This page is about a different car, the 2010 Dodge Charger and 2010 Chrysler 300. However, it is still accessible from the selected car via links, so may be relevant.
For the MDS to enable the 4 cylinder mode, the oil pressure has to be approximately 25 psi. For the MDS to remain enabled in the 4 cylinder mode the engine oil pressure can not drop below 23.2 psi. If the oil pressure drops below 23.2 psi while the, the MDS will be disabled.