It seems by the multiple posts I have read in the past on this forum, many many issues seem to resolve themselves by the installation of a new battery. Don't know why, some seem to think it's also the cleaning up of the ground and power points in the process, thus reducing line resistance, and not just having a new voltage level supplied to the electronics. Corrosion can do some weird sh!t to the system. And at 8 years, I would think this would be a no-brainer item to replace. 
(On my old 08 I replaced the ground wire with a newer thicker gauged one too.)
(On my old 08 I replaced the ground wire with a newer thicker gauged one too.)
