A connection monitoring system and method for a vehicle high voltage energy storage system is disclosed. The method performs a check, at initial connection of the high voltage energy storage system, to insure that the vehicle high voltage wiring system is fully connected and without short circuits prior to allowing full current to the vehicle and normal vehicle operation. The method switches in a resistor to limit current flow between the high voltage energy storage system and the vehicle high voltage wiring, and measures the voltage and a voltage rise time across the resistor. The voltage and the voltage rise time across the resistor are used to determine if a short circuit is present, and if so the high voltage energy storage system is disconnected to protect the vehicle and its users.