Need your expertise to determine if it is possible to establish the date and time of a truck accident with data from any of the onboard devises. The actual time of the crash has turned into a major legal dispute and establishment of the time of the crash will have major impact upon the parties to the issue. The crash, a single vehicle accident, occurred between 10:00PM on Saturday Feb. 11, 2012 and 4:00 AM Sunday Feb. 12, 2012 in a remote area.The sole occupant was knocked unconscious and has no recollection of the event. It has not been possible to reconstruct a timeline from other sources. The 2009 Chevrolet Silverado, 1/2 ton, Crew Cab, 4X4, VIN 3GCEK33389Gxxxxxx was equipped with almost every option available including On-Star and a factory radio system withGPS. The owner did NOT subscribe to On-Star and the service was inactive. On-Star customer assistance says that if the On-Star service were inactive, none of the onboard devices such as Advanced Automatic Crash Notification (AACN) or Air BagDeployment could initiate a call to On-Star’s call center. We have explored the extraction of the data captured by the Sensing and Diagnostic Modules (SDM.) While this module contains captures a lot of data about the crash event it does not provide a date/time stamp as to the occurrenceof the event. The Engine Control Module (ECM) sometimes has time/date information stored, however, the clock appears to re-set anytime battery power is removed. Cannot prove, in a courtroom, that the battery power has never been disconnected since the crash. Is there any other device that would react to the onset of the crash and provide a link to the establishment of the time of the crash? Maybe the GPS? I hope some of you can provide insight to an answer.