The security system has a code in the ignition key compared against a code in the vehicle security system to unlock the security system if the codes are similar. The security system is extended by recording the number of failed comparisons and by operating a security block when the count reaches a selected value. The non-compliance count is reset after a preset number of correct comparisons. A more secure system uses two sets of codes, with the counts representing the total number of failed or correct comparisons. The codes can be updated periodically.
