changing battery and ecu reflash
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Joined: Oct 2009
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cl600
changing battery and ecu reflash
hi, my friend has a 2002 c320 and he recently diconnected his battery before changing his alternator. after reconnecting the battery his car wouldn't start. he towed it to his tech who said disconnecting the battery caused his ecu to lose all memory and that it had to be reflashed. his mechanic said when changing alternator, or battery on mercedes you must put a charger through the cigarette lighter so you don't lose the computer memory and need a reflash. i find this very odd! i've personally disconnected my battery multiple times for hours while recharging the battery on my 2004 cl. i've also read about folks disconnecting their batteries for multiple hours to reset the computer. this is the first i've heard about charging the car through the cigarette lighter when disconnecting the battery, or alternator. any validity to this? i do realize that charging through the cigarette lighter will save the radio presets and clock as well as the window settings and keep the memory in the ecu stored, but if you don't do it is it possible to lose all memory in the ecu causing a no start and having to completely reflash the computer in order to start and run the car?
