This Preliminary information communicates During inspection of the vehicle for an unrelated concern the technician may notice that one or more of the following Cylinder Deactivation Performance DTC(s) P3498, P3499, P349A, P349B, P349C, P349D, P349E, or P349F may be set in history. and not requesting MIL. If any of these DTCs are requesting the MIL, please follow appropriate service information for diagnosis & repair.  This condition may be caused by the ECM hardware disabling the cylinder deactivation outputs for an ignition cycle due to low voltage transient during crank & inadvertently causing one of the DTCs to set during an ignition cycle.Â
