Have had this truck for 5 years and was worried it had some electrical gremlins. So infrequent enough to establish any good ideas as to its cause. ScanGuage got lost communication codes, etc. Looking back now it always happens right after releasing parking brake. This last trip it did it on releasing parking brake so I pulled over set parking brake and shut truck off. Fired back up all was normal until releasing parking brake again. This makes total sense. Going to plug in scan guage again and ease the parking brake from now on. Will update thread over time to confirm this. Been a tremendous help Cheico with this invaluable info.