Distronic discharges the battery.
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Joined: Apr 2023
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w221 s550
Distronic discharges the battery.
Hello everyone.
I need your help with my mb w221 2006 WDD2210561A020779
I have a problem: in the morning, I couldn't open the car, it didn't respond to the key. The rear battery was dead.
The battery is new. I checked for leaks with a multimeter and found a leak of 2 amps! I started removing fuses one by one from the rear SAM and found that when I removed fuse:
146 - Control unit recognition of trailer presence 25A
the car went to sleep. When I put the fuse back in, the leak returned.
According to the schematic, fuse 146 controls the recognition of a trailer. If I remove the neighboring fuse:
142 - Control unit PTS (Parktronic) Distronic Plus: Radar sensor control unit (SGR),
the leak also goes away and the car goes to sleep.
I took apart the distronic/parktronic module on the right side of the trunk (I don't know if it's called the LOC or SGR) - it's clean, like new. I sprayed contact cleaner on the contacts, but nothing changed.
If I disconnect the module completely, the leak doesn't go away. However, if I remove one of the two fuses, everything is fine.
I disconnected the rear distronic modules (the plug next to SGR module) - the leak dropped to 1.25A.
I disconnected the front distronic modules (under the bumper, to the right behind the fender liner) - the leak disappeared completely and the car went to sleep.
That is, only when I disconnect both front and rear bumper modules or remove one of the two fuses, the leak disappears.
Where should I look? What should I do?
P.S. About a week ago, I started having problems with the electronic board on the gearbox (the reverse stopped plugging in properly). They told me to keep an eye on it and if anything, replace the board. Maybe it's all related?"
Please help! Thanks in advance!
I need your help with my mb w221 2006 WDD2210561A020779
I have a problem: in the morning, I couldn't open the car, it didn't respond to the key. The rear battery was dead.
The battery is new. I checked for leaks with a multimeter and found a leak of 2 amps! I started removing fuses one by one from the rear SAM and found that when I removed fuse:
146 - Control unit recognition of trailer presence 25A
the car went to sleep. When I put the fuse back in, the leak returned.
According to the schematic, fuse 146 controls the recognition of a trailer. If I remove the neighboring fuse:
142 - Control unit PTS (Parktronic) Distronic Plus: Radar sensor control unit (SGR),
the leak also goes away and the car goes to sleep.
I took apart the distronic/parktronic module on the right side of the trunk (I don't know if it's called the LOC or SGR) - it's clean, like new. I sprayed contact cleaner on the contacts, but nothing changed.
If I disconnect the module completely, the leak doesn't go away. However, if I remove one of the two fuses, everything is fine.
I disconnected the rear distronic modules (the plug next to SGR module) - the leak dropped to 1.25A.
I disconnected the front distronic modules (under the bumper, to the right behind the fender liner) - the leak disappeared completely and the car went to sleep.
That is, only when I disconnect both front and rear bumper modules or remove one of the two fuses, the leak disappears.
Where should I look? What should I do?
P.S. About a week ago, I started having problems with the electronic board on the gearbox (the reverse stopped plugging in properly). They told me to keep an eye on it and if anything, replace the board. Maybe it's all related?"
Please help! Thanks in advance!
Last edited by xolodilnik; May 5, 2023 at 06:44 PM.
MBWorld Fanatic!
Joined: Aug 2014
Posts: 5,315
Likes: 1,672
S500
using posh diagnotics see what actul fault codes the car has ?
when diagnosed before what kit did they have - and did te clear everything?
these can produce so many error codes and so few have the right kit you could have years of codes long since irrevelant - if they are real they come back after a 10 min drive
and then under what condtions are you seeing a battery drain ? these like modern cars do - stay awake for 7 to 10 mins after you've locked it - these eat volts like mad, a diagnostic scan on some aftermarket kit takes 20 mins and its enough to flatten a brand new battery - fully loaded early ones pull 37 amps key on engine off (lights off)
when diagnosed before what kit did they have - and did te clear everything?
these can produce so many error codes and so few have the right kit you could have years of codes long since irrevelant - if they are real they come back after a 10 min drive
and then under what condtions are you seeing a battery drain ? these like modern cars do - stay awake for 7 to 10 mins after you've locked it - these eat volts like mad, a diagnostic scan on some aftermarket kit takes 20 mins and its enough to flatten a brand new battery - fully loaded early ones pull 37 amps key on engine off (lights off)
