A child restraint system includes an electronic control unit having an event data recorder for storing data relating to proper adjustment or installation of the child restraint system. The control unit receives an electrical signal from one or more sensors mounted on the child seat and determines conditions of the child seat based upon the value of the property indicated by the signal. The event data recorder is configured to store the resulting data and to allow the stored data to be retrieved in response to an inquiry. Thus, in the event of a vehicle accident or other incident, the electronic control unit may be connected to an external diagnostic unit, and the relevant data may be downloaded to the diagnostic unit for evaluation.