Weird Electrical Issue - 2011 e63
Out Of Control!!
Joined: Jun 2004
Posts: 13,799
Likes: 3,228
2014 E63S; AMS 100 octane ECU dyno tune; EDOK TCU tune; BB intakes; sprintbooster
Thread Starter
Junior Member
Joined: Nov 2022
Posts: 69
Likes: 11
From: San Antonio TX
2011 e63 AMG
Out Of Control!!
Joined: Apr 2019
Posts: 11,921
Likes: 6,769
From: Silicon Valley
W212 MY'14 M276-3.5NA @75kMi
EXTENDED REPAIR STRUGGLES...
I have just treated myself to this whole nightmare: it is sad when the best dealers can hardly get these cars running. 
Car started to have a No-Shift issue at the carwash.
Just that clue alone is enough to fix the root cause.
A collection of new ISM + Shifter modules and flat Batteries were replaced multiple times with short lived relief.
The ultimate fix was to part away from that money pit... a proven parting solution!
Let's see who picks it up to tackle "swamp gremlins"...
It sounds like CAN-B selector is not getting through busy-CGW to command CAN-C ISM "PRND" shifter.
scan > clean & disconnect
scan > reboot to sanitize
scan > done: short-term or long-term??
The fix would be to pin-point what CAN-B circuit has gone wild with crusties to drain Batts and introduce delays.
The definition of insanity is to keep going the same thing over and expect different results. Hopefully new owner won't get a third ISM replaced.
If we have learned something about these chassis CAN-Buses are built to be voltage sensitive (**) - This is not a terminal disease... ALT-LIN + Reboot + Scan/clear deals with that chaos well.
Do not let your battery get discharged by driving nor by parking .
+++ VOLTAGE IMPERVIOUS... NOT REALLY!
(**) Some of us know that Bosch designed CAN-Bus precisely to be impervious to noise and voltage swings.
CAN works with a pair of voltage differencial: "Lo/Hi".
Outcome: handmade multilayer snowball.
Car started to have a No-Shift issue at the carwash.
Just that clue alone is enough to fix the root cause.
A collection of new ISM + Shifter modules and flat Batteries were replaced multiple times with short lived relief.
The ultimate fix was to part away from that money pit... a proven parting solution!
Let's see who picks it up to tackle "swamp gremlins"...
It sounds like CAN-B selector is not getting through busy-CGW to command CAN-C ISM "PRND" shifter.
scan > clean & disconnect
scan > reboot to sanitize
scan > done: short-term or long-term??
The fix would be to pin-point what CAN-B circuit has gone wild with crusties to drain Batts and introduce delays.
The definition of insanity is to keep going the same thing over and expect different results. Hopefully new owner won't get a third ISM replaced.
If we have learned something about these chassis CAN-Buses are built to be voltage sensitive (**) - This is not a terminal disease... ALT-LIN + Reboot + Scan/clear deals with that chaos well.
Do not let your battery get discharged by driving nor by parking .
+++ VOLTAGE IMPERVIOUS... NOT REALLY!
(**) Some of us know that Bosch designed CAN-Bus precisely to be impervious to noise and voltage swings.
CAN works with a pair of voltage differencial: "Lo/Hi".
Outcome: handmade multilayer snowball.
Last edited by CaliBenzDriver; Aug 10, 2025 at 07:33 PM.
