BenzWorld Junior Member
Date registered: Sep 2018
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2014 W218 Dead battery equals dead windows and mirrors
I am hoping someone can shed some light on the following situation:
Vehicle in question is a 2014 CLS550 (W218) which worked perfectly fine UNTIL I killed the battery. Now the windows and mirror adjustments don't work.
Battery was trickle charged (per MB procedure) via jump start posts for 24hrs.
Battery holds charge, car restarts, no CEL/MIL light but I connect an Autel DS808 (fully updated and running Benz v14.0) and run a diagnostic scan.
That scan reported a few faults including
FCMU05 low voltage
Comand APS open circuit on each speaker
Central Gateway unstable CAN bus/error in CAN bus message Interior CAN bus turned off.
Scanner clears codes, verified codes don't come back, life is good until later that day when I try to roll my window down and nothing happens.
Seems all 4 windows (tried switches on all 4 doors for windows) and mirror adjustments are dead.
The all up and all down functions on the key FOB do activate the windows
I specifically checked the front SAM module and it looks fine
When I access the front left DCM (door control module) via scanner I can activate the windows (verified all 4 windows up/down within range and don't need normalizing) and adjust the mirrors.
All other mirror functions ( park assist, blind spot, turn signal, and dimming) work fine
Anybody have any ideas/suggestions before I start tearing into the door panels?
Possible there is still some current or stored fault code only a STAR scanner will be able to deal with?