Stopped driving the 2008 335i regularly and time resets on every start. Inpa codes point to potentially a bigger issue:
0x2E8D Intelligent battery sensor, signal transmission / P151A battery sensor terminal 15/30 wakeup malfunction
0x2DC3 Monitoring of terminal 15 / P15B2 Terminal 15 monitoring circuit - CAS (Car Access System)
Same codes point to IBS as discussed here:
https://www.bimmerfest.com/threads/i...-help.1258336/
Battery is 6 years old, will likely start from replacing