Patent ID: 6919812

Claim:
A key lock-in prevention system, having a warning means to give a warning of a failure to remove a key to a driver on condition that at least predetermined conditions are met; the predetermined conditions including an ignition key being in a state of insertion in a key cylinder and a driver's seat side door being open: comprising a first judging means to judge whether or not the ignition key is inserted into the key cylinder while the driver's seat side door is in the open state, on the basis of a signal detected by a key position detecting means to detect whether or not the ignition key is in a state of insertion in the key cylinder and a signal detected by a door open/closed state detecting means to detect the open/closed state of the door; wherein the warning means does not give the warning of a failure to remove a key even if the predetermined conditions are met, when the first judging means judges the ignition key to have been inserted into the key cylinder during the door's open state.