Development of a Vehicle Data Recorder for Intermittent Fault Detection and Diagnostics

Reliable detection and diagnosis of intermittent vehicle system faults has been a difficult and sometimes frustrating, time consuming, and resource intensive task. The increasing complexity of vehicle systems combined with ongoing quality and reliability improvement efforts have increased the importance of quickly finding and correcting problems.

This paper describes the design, development, and operation of a Vehicle Data Recorder (VDR) based upon specific customer requirements. The VDR is a durable solid state diagnostic tool designed and validated for use in an automotive environment. The VDR is user configured to request and monitor parameters available on the vehicle multiplex wiring bus as well as discrete analog channels. These parameters and channels can be used to conditionally trigger a fault event or the user can trigger an event manually. When a trigger event occurs, the pre- and post- trigger monitored data is stored in non-volatile memory along with time stamp information for future uploading and graphical analysis on a PC. Up to four (4) separate events of varying time duration can be recorded.

Field experience with the VDR has verified its capability to reliably detect intermittent fault conditions.