Integrated system for passive entry and keyless entry via remote control

A vehicle communication system that is mounted in the vehicle, and a portable trailer, which is carried by a user are provided. The vehicle communication system includes a control signal generator, a low frequency transmitter for transmitting a wake-up signal LF and a HF-transmitter for transmitting a UHF state message containing the vehicle condition data. The vehicle communication system sends to the LF wake-up signal from an interrogation signal. The portable trailer comprises an LF receiver, responsive to the low frequency wake-up signal, a trailer control unit for determining from the response data, and an RF transmitter for transmitting a UHF response signal including the response data. The portable trailer further comprises an RF receiver for receiving the vehicle condition data, to reproduce the vehicle condition data visually, a visual display, and a manual input key for activating the trailer control unit to generate a remote control message. The RF transmitter in the portable trailer emits a UHF control signal that contains the remote control message. The vehicle communication system further comprises an RF receiver, which responds to the UHF control signal, and a base control unit for triggering a corresponding remote control function in response to the UHF control signal.