Technical Description (Comment)
WARNING: This page is about a different car, the 2008 Mitsubishi Lancer. However, it is still accessible from the selected car via links, so may be relevant.
When the ignition switch is turned ON with the emergency operation by the inversely-inserted keyless operation key, KOS-ECU sends signals to the receiver antenna module. The receiver antenna transmits random numbers to the keyless operation key when it receives signals from KOS-ECU. If an open circuit or short to ground occurs on the wiring harness between KOS-ECU and receiver antenna at this time, KOS-ECU determines that there is a problem.