A method for automatically detecting the presence of a disconnected cable condition in an electric or hybrid electric vehicle, comprising: receiving a request to initiate a vehicle start-up sequence, said request received by a controller operatively connected to at least one contact switch (140, 142, 144, 146) of an energy storage system of greater than 50 volts, said contact switch (140, 142, 144, 146) operable to provide said energy storage system voltage power when closed, and to interrupt said energy storage system voltage power when open; operating a DC-DC converter in a boost mode to supply a test voltage on a first pair of cables (120, 122; 124, 126) connected between a first pair of terminals and a second pair of terminals, the first pair of terminals being terminals (161, 163) of the DC-DC converter and the second pair of terminals being terminals (164, 166) of the energy storage system, or the first pair of terminals being terminals (165, 167) of the energy storage system and the second pair of terminals being terminals (160, 162) of a first energy storage system voltage component of the electric or hybrid electric vehicle, a low side of the DC-DC converter being connected to a low voltage battery and said test voltage being less than 50 volts and greater than the low voltage battery voltage; using the controller to automatically compare a first voltage measured at the second pair of terminals with the test voltage to determine whether the first pair of cables (120, 122; 124, 126) is properly connected between the first pair of terminals and the second pair of terminals; using the controller to maintain said at least one contact switch (140, 142, 144, 146) in the open position to interrupt said energy storage system voltage power when the controller determines that said first pair of cables (120, 122; 124, 126) is not properly connected; and using the controller to switch said at least one contact switch (140, 142, 144, 146) to the closed position to provide power from the energy storage system when the controller determines that the first pair of cables (120, 122; 124, 126) is properly connected. receiving a request to initiate a vehicle start-up sequence, said request received by a controller operatively connected to at least one contact switch (140, 142, 144, 146) of an energy storage system of greater than 50 volts, said contact switch (140, 142, 144, 146) operable to provide said energy storage system voltage power when closed, and to interrupt said energy storage system voltage power when open; operating a DC-DC converter in a boost mode to supply a test voltage on a first pair of cables (120, 122; 124, 126) connected between a first pair of terminals and a second pair of terminals, the first pair of terminals being terminals (161, 163) of the DC-DC converter and the second pair of terminals being terminals (164, 166) of the energy storage system, or the first pair of terminals being terminals (165, 167) of the energy storage system and the second pair of terminals being terminals (160, 162) of a first energy storage system voltage component of the electric or hybrid electric vehicle, a low side of the DC-DC converter being connected to a low voltage battery and said test voltage being less than 50 volts and greater than the low voltage battery voltage; using the controller to automatically compare a first voltage measured at the second pair of terminals with the test voltage to determine whether the first pair of cables (120, 122; 124, 126) is properly connected between the first pair of terminals and the second pair of terminals; using the controller to maintain said at least one contact switch (140, 142, 144, 146) in the open position to interrupt said energy storage system voltage power when the controller determines that said first pair of cables (120, 122; 124, 126) is not properly connected; and using the controller to switch said at least one contact switch (140, 142, 144, 146) to the closed position to provide power from the energy storage system when the controller determines that the first pair of cables (120, 122; 124, 126) is properly connected.