recently changed my conductor plate in the transmission (myself 120 bucks total), had to take the car to the local euro indie to reset the ecu/tcu to get out of limp mode (250 bucks for 15 minutes of rape, i mean work).

when i get the car back the trans shifts fine but i have a host of new problems

head unit comes on, few seconds then shuts off, or go on thru to the radio and then says "system unavailable" and shuts off. often resets on off many times. sometimes just stays off. some component is also draining my battery when parked overnight. i called the indie immediately and setup to bring it back to check out the issue. bring it back and they say unrelated to them (bull**** imo) that it has a most ring fault (and 30 mins 150 bucks this time. In my area (tulsa, ok.) the dealership is atrocious and has no concern other than running your bill up, and clearly now under new ownership my indie is on the same track

so i have read probably a hundred mercedes forum posts, and downloaded dozens of pdf's etc. and i am simply not getting specific information i think would be helpful in diagnosing these issues

i cannot seem to find an accurate diagram of the fiber optic ring with component locations specific to the r230's.
have located and tested the following parts as i could using a fiber optic loop to bypass.

1. motorola vcm (under center rear console cover) a2218700826 / a2214460059 (does not have an f.o. connection)
2. audio amp (under driver side storage comp behind seat) bypassed no change
3. cd changer (in drivers side storage comp behind seat) bypassed no change
4.tuner amp becker A2208702989 driver side wall next to cd changer storage tray (cannot test, f.o. plug larger than rest, but has red lights)
5. nav unit (driver side trunk wall) bypassed no change

i am missing the tele aid / voice control that should be on the fiber optic loop, the audio gateway location, it also has the option for sat radio (has a radio code to turn on etc.) and i cannot find either of these units or model specific info on where they would be, nor any other component i may be missing.

i have also installed a replacement aux battery (old one less than a year old killed by this mess), and i tried removing / waiting / resetting fuses (#54,57,59,64,65,66,76,77) to no effect.

i need to locate any item on the ring i have not found and tested yet. any help would be appreciated. before i have to start replacing random expensive items that might not solve anything. from what i have ready the only parts i cannot test without replacement parts would be the head unit and the audio gateway ?

if it helps it is a 2006 sl65 with bose package.

 

I had the same issue. Was the amp.

 

audio amp ? (mine bypassed made no difference) or tuner amp ?

 

It's probably your tuner amp.

 

after more looking around i see some conflicting information but the part number A220 870 29 89 which comes up as a tuner amp and has the larger than normal fiber optic hookup also says "agw basis" on the product tag. is this in fact the audio gateway or just an am/fm tuner amp ?. if it is the agw then several people have said it could give the symptoms i am having.

thanks blownv8 i had in my mind already moved past this part, maybe if it is the agw the problem will get a lot smaller a lot faster (and its the easiest part to get to)