Patent ID: 6115653
Filing Date: 2000-09-05
Classification: B60W,F02D

Abstract:
A diagnostic system, particularly, for use in an engine management system, for generating a diagnostic trouble code (DTC) to indicate the operational status of a component or sub-system which is being evaluated by said diagnostic system, said diagnostic system comprising:a plurality of diagnostic function modules (DF modules), each DF module relating to a particular component or sub-system and including means for executing an evaluation routine to evaluate the operational status of the related component or sub-system and generating a DTC code or a group of DTC codes based on the result of said evaluation routine, anda diagnostic function scheduler (DF scheduler) for determining which DF module may be allowed to execute an evaluation routine at a particular time;wherein each DF module comprisesmeans for producing a ranking value dependent on the operating status of the component or sub-system being evaluated, a ranking value being generated each time an evaluation routine is performed;means for processing and storing statistical results of the ranking values obtained over a number of executions of said evaluation routine;means for evaluating said statistical results to produce evaluated data in the form of either an evaluated no-fault signal or an evaluated fault signal, andmeans for informing said DF scheduler when said evaluated data is different than the previously generated evaluated data.