This document discusses, among other things, a system and method for detecting an open secondary condition in a secondary coil of an ignition coil using a control signal received from a control input of a switch configured to control the flow of current to a primary coil of the ignition coil. In an example, the flow of current in the primary coil of the ignition coil can be controlled using an insulated gate bipolar junction transistor (IGBT), and the open secondary condition in the secondary coil of the ignition coil can be detected using a received gate voltage of the IGBT.