A method for disabling a passive entry key includes receiving a search request into an electronic control unit (“ECU”) on a vehicle to search for a passive key inside a vehicle cabin; emitting a search signal via an antenna in communication with the ECU in response to the received search request; receiving a reply signal via the antenna from the passive key inside the vehicle cabin; and recording in a memory in communication with the ECU an identification of the passive key inside the vehicle cabin in response to the received reply signal. In this method for disabling a passive entry key, the search request can be initiated by an operator at an input device. A passive entry key system is also disclosed.